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CERTIFICATION The technical material and data contained in this document were prepared under the supervision and direction of the undersigned, whose seal, as a professional engineer licensed to practice as such, is affixed below. Prepared by Joseph Tate III, P.E., P.T.O.E. Reviewed by Pierson Dewit
TABLE OF CONTENTS EXECUTIVE SUMMARY... ES-1 1. PROJECT BACKGROUND AND DESCRIPTION... 1 1.1 PROJECT INTENT AND PURPOSE... 4 2. TRAFFIC STUDY PURPOSE... 4 3. EXISTING TRAFFIC CONDITIONS... 4 4. CHRONOLOGICAL STEPS OF TRAFFIC ANALYSIS... 8 5. TRAFFIC FORECASTS... 9 6. PRELIMINARY REVIEW OF TRAFFIC FORECASTS (ADT)... 10 7. COMPREHENSIVE TRAFFIC ANALYSIS (PEAK HOUR)... 10 7.1 STUDY OPTIONS... 11 7.2 TRAFFIC VOLUMES... 12 7.3 LEVEL OF SERVICE ANALYSIS... 12 7.3.1 Assumptions... 12 7.3.2 Level of Service Results... 13 7.3.3 Further Investigation using Revised Set of Demographics... 16 8. ACCESS TO 30TH STREET... 21 9. CURSORY ANALYSIS OF POTENTIAL PARK ENTRANCES... 21 10. NEIGHBORHOOD ANALYSIS... 22 11. SUMMARY... 22 LIST OF FIGURES Figure 1. Project Area... 3 Figure 2. Existing Roadway Network... 6 Figure 3. Existing Traffic Count Information... 7 Figure 4. Traffic Analysis Zones for Project Vicinity... 17 April 2007 314-1800-014 i
TABLE OF CONTENTS CONTINUED LIST OF TABLES Table 1. LOS Criteria for Signalized Intersections... 13 Table 2. LOS Criteria for Roadway Segments... 13 Table 3. Results of LOS Analysis for Study Intersections... 14 Table 4. Results of LOS Analysis for Study Roadway Segments... 15 Table 5. Revised Set of Demographics... 18 Table 6. Results of LOS Analysis for Study Intersections for Revised Set of Demographics... 19 Table 7. Results of LOS Analysis for Study Roadway Segments for Revised Set of Demographics... 20 APPENDICES A B C D COMPASS MODEL FORECASTS BASED ON TREND DEMOGRAPHICS COMPASS MODEL FORECASTS BASED ON COMMUNITY CHOICES DEMOGRAPHICS SYNCHRO SUMMARY REPORTS COMPASS MODEL FORECASTS BASED ON REVISED DEMOGRAPHICS April 2007 314-1800-014 ii
ACRONYMS ACHD ADT COMPASS LOS Ada County Highway District Average Daily Traffic Traffic Study Community Planning Association of Southwest Idaho Level of Service April 2007 314-1800-014 iii
EXECUTIVE SUMMARY Traffic Study The is an in-depth study of the land use and multi-modal transportation opportunities connected with the extension of 30th Street in Boise, Idaho. The new alignment is being referred to as 30th Street, even though there is another 30th Street intersection on State Street and the new 30th Street actually connects to State Street at the existing Rose Street intersection. The overall study area encompasses approximately 240 acres. A series of events has created a timely opportunity to re-address the vision, land use plans and transportation needs along this corridor. The is a joint venture with the City of Boise and the Ada County Highway District (ACHD). The study boundaries for the are State Street and Irene Street to the north; the I-184 Connector to the south; the Boise River, Clithero Drive and Riviera Drive to the west; and 23rd Street to the east. The purpose of this traffic study is to evaluate the traffic operations of the identified project alternatives using the 2030 design year traffic conditions and to identify the project alternative that will provide the best traffic operations for the anticipated future conditions. Additionally, this traffic study will address potential impacts from the proposed alternative to existing neighborhoods north of State Street and adjacent to the proposed 30th Street Extension corridor. This traffic study will not identify or assess any future transit related improvements within the study boundaries. A detailed traffic analysis was completed utilizing the traffic forecasts based on the Trend demographics for three development scenarios including: No Build 3-Lane 30 th Street Extension w/ existing 4-lane 27 th Street 5-Lane 30 th Street Extension w/ a 3-lane 27 th Street No-Build Option (Option 1) This option does not adequately serve the traffic demands for the area. Also, Option 1 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. 3-Lane 30th Street Option (Option 2) The results indicate that Option 2 would result in minor improvements in LOS conditions when compared to Option 1. Also, Option 2 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. 5-Lane 30th Street Option (Option 3) Overall, the results indicated that Option 3 would result in major improvements in LOS conditions within the study area when compared to Option 1 and Option 2. Option 3 would also drastically reduce the traffic volumes on 27th Street. This would make 27th Street more conducive to the neighborhood, because the reduced traffic volumes along with the reduced number of travel lanes will make 27th Street more pedestrian friendly and less of a barrier dividing the neighborhood. This is one of the major objectives of the 30th Street Extension. For the aforementioned reasons, this study recommends the implementation of a multilane 30th Street Extension. This would include two thru-lanes in each direction with a center median and turn bays where appropriate. April 2007 314-1800-014 ES-1
5-Lane 30th Street Option w/ 3-Lane Main and 3-Lane Fairview (Charrette Option ) Overall, the results indicated that the Charrette Option would accommodate the traffic demand in the area as well as potentially make Main Street and Fairview Avenue attractive to new development. However, there are some concerns with allowing on-street parking on these arterial roadways. ACHD s general policy is to only allow on-street parking on arterials under special circumstances. If this study s vision of new land use in this area along with a new character of these roadways is achieved, ACHD may agree to allowing on-street parking on Main Street and Fairview Avenue. Also, the State Street/33rd Street intersection and the State Street/30th Street intersection are predicted to worsen to LOS E in the 2030 peak hour as a result of implementing the Charrette Option. For the aforementioned reasons, this study recommends consideration of removing one travel lane on both Main Street and Fairview Avenue. Access to 30th Street The 30th Street extension will be classified as a minor arterial roadway. It is necessary to limit the accesses/intersections along the 30th Street Extension in order for the roadway to perform optimally. Signalized intersections will be necessary on 30th Street at State Street, Main Street (currently a signalized intersection), and Fairview Avenue. All of the east-west roadways in the study area between Main Street and State Street are classified as local streets. It is recommended that the majority of these local streets not be connected to 30th Street in order to preserve the function of 30th Street and also to discourage increased traffic on these local streets. It is recommended that Idaho, Pleasanton, Stewart, and Jordan be considered for connection to 30th Street and that the other local streets not be connected to 30th Street. Neighborhood Analysis Based on the existing traffic control devices currently in place, it is reasonable to assume that additional cut-through traffic will most likely not occur in the neighborhood portion of the study area, north of State Street, between Irene Street and 23 rd Street. No additional traffic calming is recommended for this area at this time. It is recommended that separate further study be completed in the future to evaluate potential improvements on Pleasanton Avenue that would discourage cut-through traffic. At a minimum, it is recommended that a directional traffic count as well as a speed study be conducted in the summer months along Pleasanton Avenue between 27 th and 31 st Street. It is recommended that this separate study be completed in the near future, prior to the construction of the 30th Street Extension, due to the fact that traffic volumes are projected to continue to increase on Pleasanton Avenue during the next few years, especially as phases of the park are constructed. April 2007 314-1800-014 ES-2
1. PROJECT BACKGROUND AND DESCRIPTION The is an in-depth study of the land use and multi-modal transportation opportunities connected with the extension of 30th Street in Boise, Idaho. The overall study area encompasses approximately 240 acres. A series of events has created a timely opportunity to re-address the vision, land use plans and transportation needs along this corridor. The is a joint venture with the City of Boise and the Ada County Highway District (ACHD). Figure 1 identifies the study boundaries of the. The boundaries are State Street and Irene Street to the north; the I-184 Connector to the south; the Boise River, Clithero Drive and Riviera Drive to the west; and 23rd Street to the east. The Boise City Comprehensive Plan has identified a mix of land uses and densities along the 30 th Street corridor including commercial at the southern end, medium density residential and mixed use along the middle, as well as office space in the northern portion. Since the Boise City Comprehensive Plan was adopted, conditions have changed significantly in the study area. They include the following: The large car dealerships formerly located in the southern portion of the study area around Main and Fairview, near the Boise River, have moved to the western edge of Boise. This vacancy has left a sizeable amount of unutilized acreage just one mile from downtown. The City of Boise owns a vacant 8-acre site in this area. The Idaho Transportation Department (ITD) owns a 46-acre site at the northern end of the study area, bounded by State Street, the Boise River and the new 30 th Street arterial. ITD has expressed interest in participating in the planning efforts to explore the possibility of redevelopment of this site. A group of interested parties has developed a plan for a whitewater activity park on the Boise River adjacent to the study area. This plan has already attracted one new business to the study area. The City of Boise received an extraordinary gift of a 55-acre park site adjacent to the 30th Street corridor along the Boise River. The "Esther Simplot Park" will be developed as a regional park and will include athletic activity fields and still-water canoeing facilities. Much of the proposed mixed use identified in the study area is currently within the park site. The City believes that the study area in general still presents a good opportunity for mixed use development. Bus Rapid Transit and street car service are two types of transit services envisioned in the study area and these services are not likely to impact the roadway LOS. Transit options will be studied in the future under a State Street Transit and Traffic Operations Plan. The Communities in Motion Regional Transportation Plan was recently completed and the Blueprint for Good Growth Study is still ongoing at this time. Both plans envision intensifying land uses through infill development in key locations within the City of Boise. The plans envision that the more intense (higher density) land uses will support new transit services, better utilize existing infrastructure (i.e. Main/Fairview couplet) and reduce the consumption of open land in the region. This study area is a prime candidate for such intensification of land use. Current real estate trends have created momentum for redevelopment of the now underutilized lands within the study boundaries. Pressure is building for redevelopment in the near future. One new office building has already been April 2007 314-1800-014 1
completed. If redevelopment occurs before this area plan is completed, that development will not be able to take full advantage of the changed conditions. The 30th Street Extension was identified in 1995 as a part of the Bench/Valley Transportation Study. The Bench/Valley Study incorporated technical analysis, public involvement, and public agency participation to determine effective improvements to the transportation system linking the Boise River valley to the geographic bench south of the river. In conjunction with alternative transportation solutions and traffic demand management strategies, conceptual alignments and cost estimates were developed for seven road improvement corridors. The Bench/Valley Study recommended proceeding with the 30th Street Extension once development and redevelopment became prevalent in the project area. In response to development applications and inquiries, ACHD, with the aid of CH2M HILL, performed an alignment study for the 30th Street Extension between Fairview Avenue and State Street along Rose Street, in 2002. The goal of the study was to determine a preferred alignment in sufficient detail to determine conceptual right-of-way needs and impacts to future developments. The study area presents a rare opportunity for the City of Boise to plan for a new transit supported mixed use district approximately one mile from the downtown core. The adopted Communities in Motion Plan allows, through the conditional use and rezone process, the opportunity for various mixed use land development. However, the plan does not encourage or identify incentives associated with the integration of a regional transit hub within the study area. Before potential redevelopment results in missed opportunities, the City of Boise believes that now is the time for proceeding with a new vision and enabling regulations for this area. April 2007 314-1800-014 2
Figure 1. Project Area April 2007 314-1800-014 3
1.1 PROJECT INTENT AND PURPOSE The intent of the project is to use an all-inclusive process to produce a new guiding vision and enabling regulations for the study area. That vision should reflect the interests of participating stakeholders, the district residents, the proposed conditions in the study area, and the desire to intensify land use in key identified infill areas. This project will create a plan and necessary regulatory changes that will enable future development and redevelopment in the study area in keeping with the newly established vision. Another intent of this study is to work closely with ACHD and Valley Regional Transit to understand the multi-modal transportation needs of the study area so that the ACHD can proceed to design a new arterial corridor. This corridor will serve the transportation needs of the adopted vision. The study includes identifying significant land use opportunities including potential transit and mixed use nodes, connections to adjacent land uses and transportation systems, and pedestrian friendly streetscapes using an inclusive public process. Lastly, the study included preparing and leading a 30th Street Charrette that identified significant land use opportunities including potential transit and mixed use nodes, redevelopment sites, street circulation in the area, a detailed streetscape, and a pedestrian and bicycle pathway plan. The Charrette was conducted the week of February 12, 2007 pursuant to the standards of the National Charrette Institute. 2. TRAFFIC STUDY PURPOSE The purpose of this traffic study is to evaluate the traffic operations of the identified project alternatives using the 2030 design year traffic conditions and to identify the project alternative that will provide the best traffic operations for the anticipated future conditions. Additionally, this traffic study will address potential impacts from the proposed alternative to existing neighborhoods north of State Street and adjacent to the proposed 30th Street Extension corridor. This traffic study will not identify or assess any future transit related improvements within the study boundaries. 3. EXISTING TRAFFIC CONDITIONS Existing Roadway Network The existing roadway network is shown in Figure 2. Descriptions of the key roadway segments are listed below: 23rd Street 23rd Street is functionally classified as a collector with a speed limit of 30 mph. The roadway has one travel lane in each direction and parking on both sides of the road throughout the study area. 28th Street (north of State Street) 28th Street (north of State Street) is functionally classified as a collector with a speed limit of 30 mph. The roadway has one travel lane in each direction and on-street parking throughout the study area. April 2007 314-1800-014 4
Irene Street Irene Street is functionally classified as a collector with a speed limit of 20 mph. The roadway has one travel lane in each direction throughout the study area. A traffic chicane is located along Irene between 23 rd and 24 th street to allow pedestrian access to Elm Grove Park. 27th Street 27th Street is functionally classified as a minor arterial with a speed limit of 30 mph. The roadway has two travel lanes in each direction south of State Street, and one travel lane in each direction north of State Street. On-street parking is available throughout the study area. State Street State Street is functionally classified as a principal arterial with a speed limit of 35 mph. The roadway has two travel lanes in each direction and a Two-Way-Left-Turn Lane throughout the study area. Main Street Main Street is functionally classified as a principal arterial with a speed limit of 35 mph. This is a one-way roadway with four travel lanes in the westbound direction throughout the study area. Bike lanes are striped along both sides of Main Street at certain locations within the study area. Fairview Avenue Fairview Avenue is functionally classified as a principal arterial with a speed limit of 35 mph. This is a one-way roadway with four travel lanes in the eastbound direction throughout the study area. Bike lanes are striped along both sides of Fairview Avenue throughout the study area. Other Roadways All other roadways within the project limits are classified as local streets with a speed limit of 20 mph. The roadways have one lane in each direction throughout the study area. April 2007 314-1800-014 5
Existing Traffic Counts Figure 2. Existing Roadway Network Existing Average Daily Traffic (ADT) count information was obtained from ACHD for roadways within the study limits. The ADT count information provided by ACHD was the only information that was available, and was collected in recent years. Refer to Figure 3 for the existing traffic count information provided by ACHD. April 2007 314-1800-014 6
Figure 3. Existing Traffic Count Information April 2007 314-1800-014 7
4. CHRONOLOGICAL STEPS OF TRAFFIC ANALYSIS Step 1 Traffic forecast information was provided by the Community Planning Association of Southwest Idaho (COMPASS). Separate 2030 forecasts were provided based on the Community Choices demographics, as well as the Trend demographics. This was necessary to analyze the roadway network including 23 rd Street, 27 th Street, 30 th Street, Main Street, Fairview Avenue, and State Street links; and the associated intersections. There was minimal difference between the traffic forecasts using the Trend demographics in comparison to using the Community Choices demographics. Through analysis of the traffic forecast information, the project team determined that it was most appropriate to move forward using the traffic forecasts based on the Trend demographics. Step 2 A detailed traffic analysis was completed utilizing the traffic forecasts based on the Trend demographics for three development scenarios including: Step 3 No Build 3-Lane 30 th Street Extension w/ existing 4-lane 27 th Street 5-Lane 30 th Street Extension w/ a 3-lane 27 th Street The project team developed a new Revised set of demographics for the project vicinity two weeks prior to Charrette as a result of the economic and housing market analysis. This new set of demographics includes changes such as increased residential densities, and increased office and retail uses in the project vicinity. Step 4 Due to project specific guidelines that were set prior to Charrette and agreed to by both the City of Boise and ACHD, it was determined during Charrette that all additional analysis would be performed for a 30 th Street Extension with 5 lanes (2 lanes in each direction with a center turn lane). This was decided due to the fact that this was the only option that met the specific guidelines set for the project. Step 5 One unanticipated roadway development that occurred through the Charrette process was the notion of narrowing Main Street and Fairview Avenue from 4 lanes to 3 lanes with parking and bike lanes. This option was deemed necessary due to the perception that these roadways are currently wide and under-utilized. The basic premise behind this option is to make these roadways attractive to new development by providing on-street parking, street car transportation, an improved pedestrian environment, and bike lanes. This option consists of removing one travel-lane from both Main Street and Fairview Avenue and reducing the width of the travel lanes along with other changes within the right-of-way. These changes would allow for on-street parking and bike lanes on both sides of the roadway. Bus Rapid Transit and street car service are two types of transit services envisioned in the study area and these services are not likely to impact the roadway LOS. April 2007 314-1800-014 8
Step 6 During Charrette, a brief traffic analysis was completed for the option of narrowing Main Street and Fairview Avenue from 4 lanes to 3 lanes in conjunction with a 5-lane 30th Street Extension. This analysis indicated that the intersection of 27 th Street and Main Street as well as the segment of Main Street from N. 23rd Street to N. 30th Street are predicted to function at unacceptable levels-of-service (LOS F) by the year 2030. Step 7 While analyzing the problem with the projected LOS for the intersection of 27th Street and Main Street it was determined to re-model the intersection with a dual left-turn lane for the northbound left-turn movement from 27th Street onto Main Street. This change improved the projected LOS of the intersection from LOS F to LOS B. Step 8 While analyzing the problem with the projected LOS for the segment of Main Street from N. 23rd Street to N. 30th Street it was determined to re-model the roadway with right-turn lanes at the major intersections. This is possible by removing on-street parking approximately 200 feet prior to the major intersections (23rd Street, 27th Street, and 30th Street). This solution is predicted to change the LOS from F to E. However, the COMPASS model had never been re-run with a three-lane Main Street and Fairview Avenue scenario. This is important because the COMPASS Model will reallocate traffic based upon capacity, thus if Main and Fairview are limited in their capacity, the model will send traffic to other facilities to balance the traffic flow in the area. Step 9 During Charrette week the new traffic forecasts with the 3-lane scenario for Main Street and Fairview Avenue were received from COMPASS. A cursory traffic analysis was performed with the new traffic volumes for a link analysis only. This resulted in Main Street being predicted to operate at LOS C in the 2030 peak hour and Fairview Avenue being predicted to operate at LOS C/D in the 2030 peak hour. Step 10 Post-Charrette there was a need to conduct a comprehensive re-run of the SYNCHRO model. This comprehensive analysis was based upon a revised set of demographics to accurately reflect the expected condition, along with the addition of the right-turn pockets on Main Street at the major intersections, and the additional northbound left-turn lane at the intersection of 27th Street and Main Street. This resulted in Main Street being predicted to operate at LOS D in the 2030 peak hour and Fairview Avenue being predicted to operate at LOS C in the 2030 peak hour. However, westbound State Street, from N. 23rd Street to N. 33rd Street, is predicted to change from LOS D to LOS E. Also, the State Street/33rd Street intersection and the State Street/30th Street intersection are predicted to change from LOS D to LOS E in the 2030 peak hour. 5. TRAFFIC FORECASTS Traffic Forecast information was provided by COMPASS. The 2030 forecasts were based on both the Trend demographics and the Community Choices demographics, a product of the Communities in Motion planning process. Refer to Appendix A for the model output based on the Trend demographics provided by COMPASS. Refer to Appendix B for the model output based on the Community Choices demographics provided by COMPASS. April 2007 314-1800-014 9
6. PRELIMINARY REVIEW OF TRAFFIC FORECASTS (ADT) The traffic forecast information was studied to determine which set of demographics was more appropriate to carry forward for this study. The traffic forecasts for both sets of demographics were actually quite similar. However, the traffic forecasts based on the Trend demographics are the most conservative (higher projected ADT and peak hour traffic volumes). Also, the Trend demographics accounted for the most growth within the project area. For this reason ACHD in accord with the City of Boise decided that it was in the best interest of the study to proceed with using the traffic forecasts based on the Trend demographics. 7. COMPREHENSIVE TRAFFIC ANALYSIS (PEAK HOUR) The study intersections and roadway segments were analyzed using Trafficware s Synchro 6 (build 614) software program. SYNCHRO s LOS calculations utilize the methodology outlined in the Highway Capacity Manual 2000 Update, and Special Report 209, Transportation Research Board. As part of this analysis, several roadways and intersections were analyzed for 2030 traffic conditions under no-build and build alternatives. The following roadway segments were included as part of the SYNCHRO network: W. State Street: N. 23rd Street to N. 33rd Street, W. Main Street: N. 23rd Street to N. 30th Street, W. Fairview Avenue: N. 23rd Street to N. 30th Street, N. 30th Street: W. State Street to W. Fairview Avenue, N. 27th Street: W. State Street to W. Fairview Avenue, and N. 23rd Street: W. State Street to W. Fairview Avenue. The following intersections were included as part of the SYNCHRO network: W. State Street at N. 33rd Street, W. State Street at N. 32nd Street (with no-build alternative), W. State Street at N. 30th Street (with build alternatives), W. State Street at N. 28th Street, W. State Street at N. 27th Street, W. State Street at N. 23rd Street, W. Main Street at N. 30th Street (with build alternatives), W. Main Street at N. 27th Street, W. Main Street at N. 23rd Street, W. Fairview Avenue at N. 30th Street (with build alternatives), W. Fairview Avenue at N. 27th Street, and W. Fairview Avenue at N. 23rd Street. April 2007 314-1800-014 10
7.1 STUDY OPTIONS Traffic Study The following three alternatives were analyzed as part of this analysis for the 2030 design year based on the COMPASS Trend demographics: Option 1: No-Build: This alternative assumes that the study area roadway network, including link and intersection channelization and geometry, would remain as it currently exists today. The 30th Street connection between W. State Street and W. Fairview Avenue does not exist with this alternative. It is also assumed that the existing speed limits and traffic control in the study area would remain as it exists today. Option 2: 3-Lane 30th Street Extension: This alternative assumes the study area roadway network would remain as it currently exists today with the following exceptions: o o o o o A new 30th Street connection between W. State Street and W. Fairview Avenue would be built to serve the north-south traffic in the study area vicinity. The proposed 30th Street corridor would be a 3-lane facility (one northbound thru-lane, one southbound thru-lane, and one two-way left-turn lane) with a 30 mph speed limit between W. State Street and W. Fairview Avenue. The intersection of W. State Street and N. 30th Street would be signalized and the channelization at this intersection would include two thru lanes with exclusive left-turn pockets in each direction along W. State Street, one northbound left-turn pocket, one northbound thru lane, one southbound leftturn pocket, and one southbound thru lane. The existing signal at the intersection of W. State Street and N. 32nd Street would be removed due to its close proximity to the proposed signal at N. 30th Street. The analysis assumed that left turn ingress and egress movements are restricted at this intersection of W. State Street and N. 32nd Street, with the left turns diverted to adjacent intersections along W. State Street. The channelization at the intersection of W. Main Street and N. 30th Street would include an additional exclusive northbound left-turn lane. The intersection of W. Fairview Avenue and N. 30th Street would be signalized and the channelization at this intersection would include an additional exclusive southbound left-turn pocket. Option 3: 5-Lane 30th Street Extension: This alternative assumes the study area roadway network would remain as it currently exists today with the following exceptions: o o A new 30th Street connection between W. State Street and W. Fairview Avenue would be built to serve the north-south traffic in the study area. The proposed 30th Street corridor would be a five-lane facility (two northbound lanes, two southbound lanes, and a two-way left-turn lane) with a 35 mph speed limit between W. State Street and W. Fairview Avenue. The intersection of W. State Street and N. 30th Street would be signalized and the channelization at this intersection would include two thru lanes with an exclusive left-turn lane in each direction along W. State Street, dual April 2007 314-1800-014 11
o o o o o o northbound left-turn lanes, one shared northbound thru/right turn lane, one shared southbound thru/right-turn lane, and one southbound left-turn lane. The existing signal at the intersection of W. State Street and N. 32nd Street would be removed due to its close proximity to the proposed signal at N. 30th Street. The analysis assumed that left turn ingress and egress movements are restricted at this intersection of W. State Street and N. 32nd Street with the left turns diverted to adjacent intersections along W. State Street. The existing signal at the intersection of W. State Street and N. 33rd Street would remain in place with the existing lane configurations. N. 27th Street would be re-striped as a three-lane facility (one northbound lane, one southbound lane, and a two-way left-turn lane) between W. State Street and W. Fairview Avenue. The corridor would have a 25 mph posted speed limit. The channelization at the intersection of W. Main Street and N. 30th Street would include an additional exclusive northbound left-turn lane and an additional northbound and southbound thru lane. The intersection of W. Fairview Avenue and N. 30th Street would be signalized and the channelization at this intersection would include an additional exclusive southbound left -turn pocket. The revised channelization at the intersection of W. State Street and N. 27th Street would eliminate one southbound departing lane. The revised channelization at the intersection of W Main Street and N. 27th Street would include four westbound lanes, one northbound left-turn pocket, one northbound thru lane, and one southbound thru lane. 7.2 TRAFFIC VOLUMES The design year used for the analysis was year 2030. 2030 traffic volumes used for the analysis were based on the p.m. peak hour turning movement volumes provided by the COMPASS travel demand model (using the Trend demographics), which was run independently for each alternative. It was noticed that turning movement volumes were missing for a few approaches/movements at some of the study intersections provided by the COMPASS model. The missing 2030 volumes were estimated using historic turning movement counts at those locations and applying an appropriate growth rate. The traffic volumes were then balanced along the W. State Street, W. Main Street, and W. Fairview Avenue corridors. 7.3 LEVEL OF SERVICE ANALYSIS 7.3.1 Assumptions The following assumptions were used in conducting the LOS analysis of the study intersections and roadway segments for the study alternatives: No pedestrian or bicycle volumes were included as part of this analysis. An intersection peak hour factor (PHF) of 0.95 was used for all study intersections. April 2007 314-1800-014 12
7.3.2 Level of Service Results The traffic stream was assumed to consist of a 2 % heavy vehicle-mix throughout the network. No bus blockages were included as part of this analysis. No blockages from adjacent street parking were included as part of this analysis. Network signal timings were optimized. Refer to Appendix C for the Synchro summary reports for all three options studied. Measures of effectiveness used to report LOS for this analysis included average delay in seconds per vehicle (sec/veh) at the study intersections and arterial speed in miles per hour (mph) along the roadway segments. Table 1 displays the LOS criteria for signalized intersections, utilized for this study. Table 2 displays the LOS criteria for roadway segments, utilized for this study. The information provided in Table 1 and Table 2 was gathered from the criteria outlined in the 2000 Highway Capacity Manual. Table 1. LOS Criteria for Signalized Intersections Table 2. LOS Criteria for Roadway Segments April 2007 314-1800-014 13
Table 3 and Table 4 summarize the results of the LOS analysis for the study intersections and roadway segments, respectively. Table 3. Results of LOS Analysis for Study Intersections April 2007 314-1800-014 14
Table 4. Results of LOS Analysis for Study Roadway Segments April 2007 314-1800-014 15
No-Build Option (Option 1) Table 3 indicates that the study intersections along W. State Street at N. 28th and N. 27th Streets would operate at LOS E and LOS F, respectively, during the peak hour under the 2030 No-Build traffic conditions. Table 4 indicates that both directions of N. 27th Street corridor, northbound movement along N. 23rd Street, and westbound movements along W. State Street and W. Main Street corridors would operate at LOS E under Option 1 during the peak hour. This option does not adequately serve the traffic demands for the area. Also, Option 1 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. 3-Lane 30th Street Option (Option 2) Under Option 2, the intersection of W. State Street and N. 27th Street would continue to operate at LOS E. The intersection of W. State Street and N. 28th Street would continue to operate at LOS F, however the average delay would decrease by approximately 10 seconds per vehicle. Under Option 2, both directions of N. 27th Street corridor, westbound movement along W. State Street, and northbound movements along N. 23rd Street and N. 30th Street corridors would operate at LOS E. The southbound movement on the 30th Street Extension would operate at LOS D. The results indicate that Option 2 would result in minor improvements in LOS conditions when compared to Option 1. Also, Option 2 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. 5-Lane 30th Street Option (Option 3) Under Option 3, all the study intersections would operate at LOS D or better under 2030 p.m. peak hour conditions. Under Option 3, westbound movement along W. Main Street and the northbound movement along N. 23rd Street would operate at LOS E under the 2030 p.m. peak hour conditions. All other segments would operate at LOS D or better. The northbound and southbound movements on the 30th Street Extension would operate at LOS C, a drastic improvement from Option 2. Overall, the results indicated that Option 3 would result in major improvements in LOS conditions within the study area when compared to Option 1 and Option 2. Option 3 would also drastically reduce the traffic volumes on 27th Street. This would make 27th Street more conducive to the neighborhood, because the reduced traffic volumes along with the reduced number of travel lanes will make 27th Street more pedestrian friendly and less of a barrier dividing the neighborhood. This is one of the major objectives of the 30th Street Extension. 7.3.3 Further Investigation using Revised Set of Demographics The project team developed a Revised set of demographics for the project vicinity based upon the findings of the economic and housing market analysis. This new set of demographics includes changes such as increased residential densities, and increased office and retail uses in the project vicinity. These changes to the demographics were formulated by the project team by visualizing potential changes to the proposed land uses in the project vicinity directly as a result of the 30th Street Extension. Figure 4 displays the traffic analysis zones for the project vicinity. Table 5 displays the assumptions utilized for the revised demographics in comparison to the Trend demographics. As shown in the table, TAZ 209 has increased population, increased households, and fewer vehicles. This reduced vehicle ownership trend is a result of a suburban to urban lifestyle shift.. April 2007 314-1800-014 16
Figure 4. Traffic Analysis Zones for Project Vicinity April 2007 314-1800-014 17
Table 5. Revised Set of Demographics Traffic forecast information was provided by COMPASS for the Revised demographics for the 5-lane 30th Street Extension with 3 lanes on Main Street and Fairview Avenue (Charrette Option) Refer to Appendix D for the model output for the Charrette Option based on the Revised demographics provided by COMPASS. April 2007 314-1800-014 18
Table 6 and Table 7 summarize the results of this LOS analysis for the study intersections and roadway segments, respectively. Table 6. Results of LOS Analysis for Study Intersections for Revised Set of Demographics April 2007 314-1800-014 19
Table 7. Results of LOS Analysis for Study Roadway Segments for Revised Set of Demographics April 2007 314-1800-014 20
As a result of this analysis, Main Street is predicted to operate at LOS D in the 2030 peak hour and Fairview Avenue is predicted to operate at LOS C in the 2030 peak hour. The northbound segment of N. 23rd Street would improve to LOS D and the southbound segment of N. 23rd Street would improve to LOS C. However, there are some concerns with allowing on-street parking on these arterial roadways. ACHD s general policy is to only allow onstreet parking on arterials under special circumstances. If this study s vision of new land use in this area along with a new character of these roadways is achieved, ACHD may agree to allowing on-street parking on Main Street and Fairview Avenue. Also, westbound State Street, from N. 23rd Street to N. 33rd Street, is predicted to worsen to LOS E. The State Street/33rd Street intersection and the State Street/30th Street intersection are predicted to worsen to LOS E in the 2030 peak hour as a result of implementing the Charrette Option. An additional westbound thru-lane on State Street would be required to improve the LOS for the two aforementioned intersections as well as the westbound segment of State Street. Overall, the Charrette Option would accommodate the traffic demand in the area as well as make Main Street and Fairview Avenue attractive to new development. Bus Rapid Transit and street car service are two types of transit services envisioned in the study area and these services are not likely to impact the roadway LOS. 8. ACCESS TO 30TH STREET The 30th Street extension will be classified as a minor arterial roadway. It is necessary to limit the accesses/intersections along the 30th Street Extension in order for the roadway to perform optimally. Signalized intersections will be necessary on 30th Street at State Street, Main Street (currently a signalized intersection), and Fairview Avenue. All of the east-west roadways in the study area between Main Street and State Street are classified as local streets. It is recommended that the majority of these local streets not be connected to 30th Street in order to preserve the function of 30th Street and also to discourage increased traffic on these local streets. It is recommended that Idaho, Pleasanton, Stewart, and Jordan be considered for connection to 30th Street and that the other local streets not be connected to 30th Street. The existing signalized intersection for ITD, located at 33rd and State Street, is the ideal location for ITD traffic to continue to get their access. There is potential for a substantial amount of additional deveoplment on the existing ITD site. This additional development may require the need for a full access intersection on 30th Street as well as an additional partial access intersection on 30th Street. ACHD guidelines for access spacing on arterial roadways will need to be followed in determining the proper location for any necessary access on 30th Street. 9. CURSORY ANALYSIS OF POTENTIAL PARK ENTRANCES The Esther Simplot Park consists of 55 acres dedicated to the City through the major contribution by the Simplot family. The conceptual plan for the park includes athletic fields, trails, and natural areas for fishing, still water canoeing and viewing of wildlife habitat. The City of Boise has partnered with interested white water enthusiasts to develop a white water facility at the park. The design of the park layout is in the initial conceptual phase. Locations for the main vehicle entrance(s) to the park off of the 30th Street Extension are still being considered. The potential locations for the main entrance(s) include Pleasanton Avenue, Stewart Avenue, and Woodlawn Avenue. It is recommended that the major access to the park be constructed at Stewart Avenue or at Woodlawn Avenue. A major entrance at one of these locations would function better than a major entrance at Pleasanton Avenue. A necessary horizontal curve of the 30th Street alignment at Pleasanton Avenue and a necessary offset intersection at April 2007 314-1800-014 21
10. NE 11. SU Pleasanton (due to the existing geometrics) make this location less desirable for the major entrance to the park. A traffic signal or an other effective traffic control treatment (i.e. roundabout) would most likely be needed at the major park entrance. An engineering study and traffic signal warrant analysis for this intersection will need to be completed during subsequent design phases of the park. Other accesses that would allow right-in and right-out movements only are also being considered for the park. ACHD s design guidelines including minimum acces spacing will be utilized during the design phase to ensure a safe and efficient design. No SYNCHRO analysis was conducted for the park entrances as a part of this study. IGHBORHOOD ANALYSIS The neighborhood portion of the study area, north of State Street, between Irene Street and 23 rd Street, was investigated to determine if the 30th Street Extension could potentially cause increased traffic in this neighborhood due to cut-through traffic. Multiple traffic control devices are currently in place in this portion of the study area. Throughout this area, two-way stop control has been implemented at alternating intersections, a result of the North End Traffic Analysis conducted in 2001. All-way stop controlled intersections also exist at multiple locations within this area. Based on the existing traffic control devices currently in place, it is reasonable to assume that additional cut-through traffic will not occur within this section of the study limits. No additional traffic calming is recommended for this area at this time. The neighborhood portion of the study area, south of State Street, between the 30th Street Extension and 23 rd Street, was also studied to determine if the 30th Street Extension could potentially cause increased traffic in this neighborhood due to cut-through traffic. The majority of the local roadways within this neighborhood do not have any prevalent characteristics that indicate the potential for additional cut-through traffic. However, Pleasanton Avenue is a relatively wide street that appears to have some characteristics of a collector roadway. The Pleasanton Avenue road section has one travel lane in each direction with on-street parking along both sides of the roadway. Idaho River Sports is located at the intersection of Pleasanton Avenue and 31 st Street and input from the public indicated that traffic volumes increase during the summer months as a result of this business. Based on this public input and the nature of the seasonal business, it is recommended that separate further study be completed in the future to evaluate potential improvements on Pleasanton Avenue that would discourage cut-through traffic, if warranted. At a minimum, it is recommended that a directional traffic count as well as a speed study be conducted in the summer months along Pleasanton Avenue between 27 th and 31 st Street. It is recommended that this separate study be completed in the near future, prior to the construction of the 30th Street Extension, due to the fact that traffic volumes are projected to continue to increase on Pleasanton Avenue during the next few years, especially as phases of the park are constructed. It is also recommended that further study be completed for Woodlawn Avenue, Regan Avenue, and Stewart Avenue in the future to evaluate potential improvements that would discourage cutthrough traffic, if warranted. If Woodlawn Avenue and Regan Avenue are not connected to 30th Street, as recommended, cut-through traffic should not be an issue. MMARY No-Build Option (Option 1) This option does not adequately serve the traffic demands for the area. Also, Option 1 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. April 2007 314-1800-014 22
3-Lane 30th Street Option (Option 2) The results indicate that Option 2 would result in minor improvements in LOS conditions when compared to Option 1. Also, Option 2 would not result in reducing traffic volumes on 27th Street, one of the major objectives of the 30th Street Extension. 5-Lane 30th Street Option (Option 3) Overall, the results indicated that Option 3 would result in major improvements in LOS conditions within the study area when compared to Option 1 and Option 2. Option 3 would also drastically reduce the traffic volumes on 27th Street. This would make 27th Street more conducive to the neighborhood, because the reduced traffic volumes along with the reduced number of travel lanes will make 27th Street more pedestrian friendly and less of a barrier dividing the neighborhood. This is one of the major objectives of the 30th Street Extension. For the aforementioned reasons, this study recommends the implementation of a multilane 30th Street Extension. This would include two thru-lanes in each direction with a center median and turn bays where appropriate. 5-Lane 30th Street Option w/ 3-Lane Main and 3-Lane Fairview (Charrette Option) Overall, the Charrette Option would accommodate the traffic demand in the area as well as potentially make Main Street and Fairview Avenue attractive to new development. However, there are some concerns with allowing on-street parking on these arterial roadways. ACHD s general policy is to only allow on-street parking on arterials under special circumstances. If this study s vision of new land use in this area along with a new character of these roadways is achieved, ACHD may agree to allowing on-street parking on Main Street and Fairview Avenue. Also, the State Street/33rd Street intersection and the State Street/30th Street intersection are predicted to worsen to LOS E in the 2030 peak hour as a result of implementing the Charrette Option. For the aforementioned reasons, this study recommends consideration of removing one travel lane on both Main Street and Fairview Avenue. Access to 30th Street The 30th Street extension will be classified as a minor arterial roadway. It is necessary to limit the accesses/intersections along the 30th Street Extension in order for the roadway to perform optimally. Signalized intersections will be necessary on 30th Street at State Street, Main Street (currently a signalized intersection), and Fairview Avenue. All of the east-west roadways in the study area between Main Street and State Street are classified as local streets. It is recommended that the majority of these local streets not be connected to 30th Street in order to preserve the function of 30th Street and also to discourage increased traffic on these local streets. It is recommended that Idaho, Pleasanton, Stewart, and Jordan be considered for connection to 30th Street and that the other local streets not be connected to 30th Street. April 2007 314-1800-014 23
APPENDIX A COMPASS MODEL FORECASTS BASED ON TREND DEMOGRAPHICS
APPENDIX B COMPASS MODEL FORECASTS BASED ON COMMUNITY CHOICES DEMOGRAPHICS
APPENDIX C SYNCHRO SUMMARY REPORTS
APPENDIX D COMPASS MODEL FORECASTS BASED ON REVISED DEMOGRAPHICS