Nixon, Green, and Dhu Varren Roads Intersection Improvement Study
Background Public Discussion October 2013 Over 100 people participated Summary available at project website Intersection Study Started September 2014 Study Purpose: Address existing Public Concern Future Traffic Demands
Intersection Improvement Goals Improve Operational Efficiency Create a Pedestrian-friendly Environment Accommodate Bicycle Traffic Provide Accessibility Minimize Environmental Impacts
Nixon Road Dhu Varren Road Green Road
Option Development Complete Streets design pedestrians and cyclists Mitigation of any wetland impacts Provide for predicted future traffic volumes
2035 Future Traffic Volumes Background Traffic Growth Anticipated Traffic Volume generation: Woodbury Club Apartments Nixon Farms Condominiums North Sky Barton Green Brewer Northside Glen
Nixon Road Wetlands Dhu Varren Road Existing alignments
Reconfigured alignment
Concepts Considered Traffic Sig nal
1. Leave as is 2. Two-way stop
3. Aligned all stop
4. Oval Roundabout, existing intersection configuration 5. Roundabout (circular), reconfigured intersection alignment
5. One lane roundabout 700 Vehicles (peak hour) 500 Vehicles (peak hour)
6. One lane roundabout with bypass lane
7. Offset Signal 8. Aligned Signal Traffic Sig nal Traffic Sig nal
Concepts Considered Status quo Leave as is Two-way Stop Control Aligned All-way Stop Control Oval Roundabout One Lane Roundabout Roundabout w/ Bypass Lane Traffic Sig nal Offset Signal Aligned Signal
Traffic Operations Assessment Level of Service A B C D E F Description Excellent operation with minimal or no delays. Typical operation with some delays. Congested situation, improvements are usually considered. Source: Highway Capacity Manual
Options Level of Service Status quo Leave as is F Two-way Stop Control F Aligned All-way Stop Control F (am peak/pm peak) Oval Roundabout E/C One Lane Roundabout E/C Roundabout w/ Bypass Lane C/C Traffic Sig nal Offset Signal Aligned Signal E/E C/B
Options Shortlist Status quo Leave as is F Two-way Stop Control F Aligned All-way Stop Control F (am peak/pm peak) Oval Roundabout E/C One Lane Roundabout E/C Roundabout w/ Bypass Lane C/C Traffic Sig nal Offset Signal Aligned Signal E/E C/B
Roundabout with Bypass Lane
Traffic Signals Traffic Sig nal
Criteria Evaluated Future Traffic Operations (2035) Construction Cost Ongoing Operational Costs Right-of-way Needs Pedestrians and Cyclists Transit Safety Environmental
Future Traffic Operations Peak Period Level of Service Signal Roundabout AM C C PM B C
Future Future Traffic operations Operations Study Intersection Bluett Drive Intersection
Construction Cost Overall cost $0.8-1.2M (including Dhu Varren Road Realignment) Signal Roundabout Construction Roundabout more expensive ($0.2M) Operations No Significant Difference
Right-of-way Needs Signals Roundabout
Pedestrians and Cyclists Signal Roundabout Vehicle Speeds Unadjusted Slower Driver interaction Crossing Distance Less Three lanes at a time More One lane at a time Bicyclists On and off-road provision Pedestrians/ Accessibility Protected Phase Capability Challenge for visually impaired pedestrians (ongoing research) Source: FHWA Safety
Transit Transit Signal Roundabout Following review by AAATA no significant difference
Vehicle Safety Signal Roundabout Safety More familiar Slightly less predicted crashes
Environmental Signal Roundabout Environmental Impact Less Impervious Surface (compared to roundabout) Less Emissions (by maintaining traffic flow)
Option Comparison Criteria Signal Roundabout Future Traffic Operations Construction Cost Ongoing Operational Costs Right-of-way Needs Pedestrians and cyclists Transit Vehicle Safety Environmental
Questions Traffic Sig nal