TECHNICAL MEMORANDUM To: Chandra Ravada, East Central Intergovernmental Association From: David Veneziano, Iowa LTAP Safety Circuit Rider and the RSA Team Date: August 6, 2018 Re: Safety Assessment Intersections at John Deere Dubuque Works INTERSECTION SITE SAFETY ASSESSMENTS DUBUQUE COUNTY, IOWA May 14, 2018 Following a request from the East Central Intergovernmental Association (ECIA), the Iowa Local Technical Assistance Program (LTAP) Safety Circuit Rider assembled a safety assessment team to review crash data, geometric data, and to complete a field review of the intersections around the John Deere Dubuque Works, north of the City of Dubuque, Iowa. Figure 1 presents a map of the intersection locations. This memorandum documents the crash data, existing conditions, and the observations and discussions of the assessment team. It is intended to be a list of ideas for consideration that might be further explored and/or analyzed. The members of the assessment team included David Veneziano from Iowa LTAP; Paul LaFleur of the Federal Highway Administration; and Larry Grant from the Iowa Governor s Traffic Safety Bureau (GTSB). They were joined in a pre-assessment meeting by Anthony Badgert, Dubuque County Engineer, Bob Schiesl, City of Dubuque, Chandra Ravada, East Central Intergovernmental Association, and Bob Keller, Ernest Jackson and Steven Mai from John Deere. A brief pre-assessment meeting was held at the John Deere Dubuque Works Visitor Center prior to the site visit. This meeting began at 9:30 a.m. During this initial meeting, a general overview on the plant site and its history, the intersection locations, concerns, and the field review activities was covered. Assessment team members also reviewed crash and geometric data at the meeting, and this information was briefly discussed. There are around 3,000 people at the plant site each day, including 2,700 employees and additional contractors, etc. Additionally, the plant is serviced by approximately 270 trucks per day. This results in a good amount of traffic to and from the facility each day. The primary concern for the overall site is the plant shift change that happens between 2:00 p.m. and 4:00 p.m. At around 2:30 p.m., the South Lot, where most employees park, sees about 650 vehicles trying to exit, mostly through left turns, and that starts to impact the main and north entrances to the plant complex. The goal is to get people off the property safely and efficiently. 1
Production is reduced on weekends, so it is weekday traffic that is the concern. Future lot expansion at the north end of the facility is likely to affect traffic patterns and use, and this is an additional concern. A second issue is the truck traffic at the site. Most shipping of equipment occurs during the day, but plant deliveries occur around the clock. At the south end of the site, left turning trucks are a particular concern, as they encounter a grade to the southwest immediately after turning onto John Deere Road. Typically these trucks are hauling new equipment from the plant and are heavy. The grade that they encounter on John Deere Road slows them down and creates a speed differential with traffic approaching from behind. In light of the concerns expressed by the group during the pre-meeting, a review of six intersections in the vicinity of the plant was completed. All of these intersections were located along county roadways. The intersections reviewed by the RSA team included the following: Herber Road and North Lot Entrance Herber Road and Visitor Lot Entrance Herber Road/Deere Road and D 10 Deere Road and South Lot Entrance Deere Road and Peru Road Peru Road and South Lot/Truck Entrance At approximately 10:30 a.m. the team walked to the first intersection site. The team conducted the field review of the intersections from approximately 10:30 a.m. to 12:15 p.m. At the time of the assessments, conditions were clear and dry, with moderate traffic passing through the intersections. This allowed observation of traffic interactions at each site, and assessment team members were able to view the sites from different positions and locations, study site characteristics, and note the potential issues and concerns that they saw. In addition to the site visit, the City of Dubuque coordinated extensive traffic and speed data collection at each of the intersections in the weeks following the field review. These data are discussed within each of the respective sections that follow. 2
Figure 1. Map of intersection Site Locations (source: www.google.com/maps) REVIEW OF SITE CHARECTERISTICS Herber Road and North Lot Entrance Herber Road is a north-south roadway that curves northwest north of the intersection. The North Lot Entrance is an east-directional roadway. The north lot area serves a combination of employee parking and materials delivery access. Materials delivery include trailer movements to and from a cross dock facility in the northeast corner of the intersection. The intersecting roadways meet at approximately a right angle. The east approach of the North Lot Entrance is stop-controlled. The traffic counts on the east, north, and south approaches of this intersection are approximately 1,168, 1,000, and 2,208 average annual daily traffic (aadt), respectively (2018 data). The speed limit on Herber Road is 45 mph, while the North Lot Entrance is unposted (25 mph). The average speeds east, north and south legs of the intersection were 20 mph, 48.5 mph, and 42 mph, respectively (2018 data). Figure 2 shows an aerial photo of the intersection. 3
Figure 2. Intersection of Herber Road and North Lot Entrance (source: www.google.com/maps) Crash data was collected for the years 2008 through 2018. This data indicated that one crash occurred at this intersection during the time period. This crash was characterized as run off the road right and its severity was property damage only. The crash occurred on a weekday under dry conditions. Images from the intersection are shown in Figure 3. North Lot Entrance Westbound Herber Road Northbound 4
Herber Road Southbound Figure 3. Site photos of Herber Road and North Lot Entrance approaches (images: Veneziano) Herber Road and Visitor Lot Entrance Herber Road is a north-south roadway, while the Visitor Lot Entrance is an east-directional roadway. The visitor lot entrance services various employee parking areas, including a connection to the South lot. This entrance was constructed approximately 2014 in conjunction with a reconstruction of the Herber Road/Deere Road and D10 intersection. The roadways meet at approximately a right angle. The east approach of the Visitor Lot Entrance is stop-controlled. The traffic counts on the east, north, and south approaches of this intersection are approximately 2,281, 2,201, and 4,122 aadt, respectively (2018 data). The speed limit on Herber Road is 45 mph, while the North Lot Entrance is unposted. The average speeds east, north and south legs of the intersection were 24 mph, 44 mph, and 39.5 mph, respectively (2018 data). No crashes occurred at this intersection between its construction and 2018. Figure 4 shows an aerial photo of the intersection, while images from the intersection are shown in Figure 5. Figure 4. Intersection of Herber Road and Visitor Lot Entrance (source: www.google.com/maps) 5
Visitor Lot Entrance Westbound Herber Road Northbound Herber Road Southbound Figure 4. Site photos of Herber Road and Visitor Lot Entrance approaches (images: Veneziano) Herber Road/Deere Road and D10 Herber Road/Deere Road is a north-south roadway, while D10 is a west-directional roadway. Formerly, there was an east approach to this intersection, which consisted of a parking lot entrance running northeast from the intersection. This was removed in approximately 2014, and the intersection took on a T configuration. The roadways meet at a slight angle, and Herber Road curves slightly north to northwest north of the intersection. The west approach of D10 is stop-controlled. The traffic counts on the west, north, and south approaches of this intersection are approximately 1,227, 4,236, and 4,480 aadt, respectively (2018 data). The speed limit on Herber Road/Deere Road is 45 mph, while the speed limit on D10 is 55 mph. The average speeds west, north and south legs of the intersection were 35.5 mph, 41 mph, and 46.5 mph, respectively (2018 data). Figure 5 shows an aerial photo of the intersection. 6
Figure 5. Intersection of Herber/Deere Road and D10 (source: www.google.com/maps) Crash data was collected for the years 2008 through 2018. A total of 11 crashes occurred at this intersection over that time period. Prior to the 2014 reconstruction, six crashes occurred, while five crashes occurred after the reconstruction. Three crashes were minor injury, seven were property damage only, and one was possible/unknown injury. Ten of the crashes occurred during weekdays, occurring throughout the day. Five crashes involved some form of failure to yield the right of way, one involved an animal, one involved excessive speed, one involved driving too fast for conditions, one involved an improper turn, one was run off the road right, and one was run off the road left. Six crashes involved multiple vehicles. Images from the intersection are shown in Figure 6. D10 Eastbound Herber Road Northbound 7
Deere Road Southbound Figure 6. Site photos of Herber Road/Deere Road and D10 intersection approaches (images: Veneziano) Deere Road and South Lot Entrance Deere Road is a north-south roadway, while the South Lot Entrance is an east-directional roadway. The roadways meet at approximately a right angle. The east approach of the South Lot Entrance is stop-controlled. The traffic counts on the east, north, and south approaches of this intersection are approximately 1,802, 4,369, and 5,682 aadt, respectively (2018 data). The speed limit on Deere Road is 45 mph, while the speed limit for the South Lot Entrance is 25 mph. The average speeds east, north and south legs of the intersection were 30.5 mph, 46.5 mph, and 47 mph, respectively (2018 data). No crashes occurred at this intersection between 2008 and 2018. Figure 7 shows an aerial photo of the intersection, while images from the intersection are shown in Figure 8. Figure 7. Intersection of Deere Road and South Lot Entrance (source: www.google.com/maps) 8
South Lot Entrance Westbound Deere Road Northbound Deere Road Southbound Figure 8. Site photos of Herber/Deere Road and South Lot Entrance approaches (images: Veneziano) Deere Road and Peru Road Deere Road is a north-south roadway, while Peru Road is an east-directional roadway. The roadways meet at a skewed angle, with Peru Road entering the intersection in a southeast to northwest direction. The east approach of Peru Road is stop-controlled. Peru Road is the route taken by trucks when picking up completed machinery for shipment, which translates into a number of heavy loads passing through this intersection. The traffic counts on the east, north, and south approaches of this intersection are approximately 1,863, 5,841, and 5,138 aadt, respectively (2018 data). The speed limit on Deere Road is 50 mph, while the speed limit on Peru Road is 45 mph. The average speeds east, north and south legs of the intersection were 38 mph, 48.5 mph, and 47.5 mph, respectively (2018 data). Figure 9 shows an aerial photo of the intersection. 9
Figure 9. Intersection of Deere Road and Peru Road (source: www.google.com/maps) Crash data was collected for the years 2008 through 2018. Two crashes occurred at this intersection over that time period. One crash was property damage only, and one was possible/unknown injury. The crashes occurred on a Tuesday and Saturday, both during daylight hours under dry conditions. One crash was characterized as run off the road straight, while the other was attributed to following too closely. One crash was single vehicle, while the other involved two vehicles. Interestingly, despite all of the truck traffic that passes through this intersection (including slow turning movements), none of the crashes involved a truck. Images from the intersection are shown in Figure 10. Peru Road Westbound Deere Road Northbound 10
Deere Road Southbound Figure 10. Site photos of Deere Road and Peru Road intersection approaches (images: Veneziano) Peru Road and South Lot Entrance Deere Road is a north-south roadway, while the South Lot Entrance is an east-directional roadway. The roadways meet at approximately a right angle. The east approach of the South Lot Entrance is stop-controlled. The traffic counts on the east and west approaches of Peru Road are 2,470 and 1,664 aadt, respectively (2018 data). Traffic counts on the South Lot Entrance and semi entrance are approximately 1,241 and 269 aadt, respectively. The speed limit on Peru Road is unposted, while the speed limit for the South Lot Entrance and semi entrance are 25 mph. The average speeds east and west legs of the intersection are 35.5 mph and 39 mph, respectively (2018 data). Average speeds on the South lot Entrance are 33 mph, while the semi entrance average speeds are 17..5 mph (2018 data). No crashes occurred at these intersections between 2008 and 2018. Figure 11 shows an aerial photo of the intersection, while images from the intersections are shown in Figure 12. 11
Figure 11. Intersection of Peru Road and Peru Road (source: www.google.com/maps) Peru Road Westbound South Lot Entrance Southbound Peru Road Eastbound South Lot Entrance Southbound Figure 12. Site photos of Peru Road and South Lot Entrances (images: Veneziano) 12
DISCUSSION/OBSERVATIONS AND SUGGESTIONS The review team discussed their observations and findings during and after the site visits and agreed that there were several issues present that should be addressed. The following text summarizes the observations of the team for the intersections and segment that were visited, and suggested improvements that can be pursued to address them. Herber Road and North Lot Entrance While this site does not have an extensive crash history, there is still the potential for crashes to occur with the frequent cross dock truck traffic entering and existing the driveway to the north of and immediately adjacent to the intersection. Trucks being moved to or from this facility were observed by the team during the site visit. At present, these movements enter or exit the cross dock yard, use a short portion of Herber Road to reach the north lot entrance, and then use that roadway to access the plant. This creates a potential conflict between slow moving truck traffic and faster moving through traffic that may or may not expect trucks to be present. While a Heavy Equipment Crossing warning sign was present, this sign was faded. The roadway surfaces were in good condition, although some pavement edge drop off was observed along portions of Herber Road. Non-standard overhead lighting was present in the northeast corner of the intersection. The pole that this lighting was mounted on was close to the edge of the roadway. Additionally, an old utility pole on the west side of Herber Road was present but not used for existing transmission or lighting. A John Deere North Entrance visitor sign appeared to be located within the County s right of way. The North Lot Entrance pavement also had worn pavement markings. Suggested improvements to address the issues identified include: John Deere could create a new exit from the cross dock facility that exits directly onto the North Lot Entrance roadway or on the east end of the facility. Perform maintenance as needed to address pavement edge drop off. The overhead lighting pole in the northeast corner of the intersection could be moved back from the roadway, and more conventional intersection lighting could be used. The old utility pole on the west side of Herber Road could be removed. The faded Heavy Equipment Crossing warning sign could be replaced with new sheeting. Check whether the John Deere North Entrance visitor sign is within the county right of way. It could be moved back from the roadway if it is. John Deere could repaint the worn pavement markings on the North Lot Entrance roadway. 13
Herber Road and Visitor Lot Entrance During the initial review of this intersection, there appeared to be good sight triangles from vehicles on all approaches. However, after being present at the site for a time, cars approaching northbound on Herber Road were observed to disappear in the horizontal curve to the south of the intersection when viewed from the Visitor Lot Entrance roadway. Some pavement edge drop off was noted along Herber Road. A Main Lobby visitor sign appeared to be located within the County s right of way. The North Lot Entrance pavement also had some worn pavement markings. Suggested improvements to address the issues identified include: A sight distance study could be conducted to determine whether there is an issue viewing approaching northbound vehicles on Herber Road from the Visitor Lot Entrance roadway (when facing west). Determine whether adequate time is available for leftturning traffic to cross the northbound lane safely if a sight distance issue is present. Perform maintenance as needed to address pavement edge drop off. Check whether the Main Lobby visitor sign is within the county right of way. It could be moved back from the roadway if it is. John Deere could repaint the worn pavement markings on the North Lot Entrance roadway. Herber Road/Deere Road and D10 This intersection has had a fairly recent geometric reconfiguration, and that has helped simplify driver workload when navigating the site. However, there are still areas of the intersection that remain unchanged. A wide radius corner in the southwest quadrant of the intersection creates a very wide intersection throat, and two Stop signs have been posted on either side of the roadway, presumably to ensure that at least one is within a driver s field of vision as they approach. These Stop signs appeared to be worn. Black and white Cross Traffic Does Not Stop plaques were also posted with the Stop signs, and these supplemental signs appeared to be worn. The horizontal curve on Herber Road/Deere Road through the intersection is fairly short. No chevrons for that curve are posted, nor are there any curve warning signs present. Three rumble strips were installed on the D10 west approach. These were in good condition. The D10 route marker west of the intersection was deteriorated. An Oncoming Traffic Does Not Stop warning sign was posed for northbound traffic south of the intersection. This sign dates back to the period prior to the intersection reconfiguration. Some pavement edge drop off was noted along all approaches to the intersection. Suggested improvements to address the issues identified include: 14
The west approach of D10 could be straightened and the wide radius in the southwest corner pulled in. The right side Stop sign on the roadway would be moved correspondingly, and the Stop sign on the left side of the roadway could be removed. Chevrons could be added to delineate the horizontal curve on Herber Road/Deere Road and provide a visual cue that the old intersection/alignment is no longer in place. Curve warning signs could be added on Herber Road/Deere Road. The Oncoming Traffic Does Not Stop warning sign could be removed. The D10 route marker west of the intersection could be replaced. Perform maintenance as needed to address pavement edge drop off. The black and white Cross Traffic Does Not Stop plaques could be replaced with yellow and black plaques presenting the same message at some point in the future. The original use of the black and white regulatory colors for this sign changed to yellow and black warning colors in the 2003 edition of the Manual on Uniform Traffic Control Devices. Deere Road and South Lot Entrance This intersection sees a heavy amount of traffic, particularly during the afternoon shift change. The majority of traffic leaving this lot turns left onto Deere Road. A right turn lane along Deere Road for northbound traffic entering the lot has been installed, but exiting traffic waiting to turn left still needs to wait for approaching northbound traffic to commit to turning right by entering this lane before they can begin their maneuver. The result is the potential for queues to form from left turn traffic backing up. Deere Road has a paved shoulder area on the west side of the roadway which allows southbound traffic to pass by left turning traffic waiting to turn into the South Lot Entrance. Nonstandard overhead lighting was present in the southeast quadrant of the intersection. The post for this lighting was located close to the roadway edge. The Stop sign at the entrance was leaning. Its post did not appear to be breakaway and was sunk in a concrete base. The lot entrance sign in the southeast quadrant was located close to the roadway and appeared to be located in the county s right of way. The existing pavement markings on the South Lot Entrance pavement were worn. The D10 route marker to the north of the intersection was leaning. Shoulder erosion from recent rains was observed in the northeast quadrant of the intersection down into the roadside ditch. Suggested improvements to address the issues identified include: If exiting traffic continues to grow (particularly left turn volumes), a traffic signal could be considered. Alternative intersection designs could be investigated. For example, a Continuous Green T- Intersection 1 (also referred to as a Florida Tee) might be an option for this location since it allow for the channelization of the left turn movement leaving the South Lot Entrance. The overhead lighting pole in the northeast corner of the intersection could be moved back from the roadway, and more conventional intersection lighting could be used. 1 For more information on this design, visit: https://www.fhwa.dot.gov/publications/research/safety/16036/16036.pdf 15
John Deere could straighten the stop sign at the intersection. The post and installation could be converted to a breakaway design. The sign could be moved forward as well. Check whether the lot entrance sign is within the county right of way. It could be moved back from the roadway if it is. The South Lot Entrance pavement markings could be repainted. The D10 route marker could be straightened. Shoulder maintenance could be performed as needed. Deere Road and Peru Road As discussed earlier, this intersection sees a good amount of truck traffic to and from the plant, including completed equipment loads leaving for delivery. These departing loads are impacted by an uphill grade to the south of the intersection when turning onto Deere Road, which results in those trucks moving slowly on that grade. During the visit, the team observed several such loads leaving and encountering the grade. Peru Road intersects Deere Road at a skewed angle. As a result, northbound trucks turning right to access the plant via have a tight radius to traverse. Evidence of trailer off-tracking was noted during the site visit in the southeast corner of the intersection. Paved shoulders were present along both sides of Deere Road. A driveway was present on the west side of Deere Road approximately 1000 feet south of the intersection. Some pavement edge drop off and erosion were observed on the shoulders of Peru Road. Rumble strips were present on the east approach of Peru Road, but these were worn. The Stop sign on Peru Road was leaning to the north, and no stop bar was present. The double arrow warning sign on the west side of the intersection was faded and worn. The No Passing Zone pennant on Peru Road for eastbound traffic was leaning. Suggested improvements to address the issues identified include: A potential climbing lane for southbound trucks could be investigated. A wider radius for right turning trucks could be added in the southeast quadrant of the intersection. Turning Truck Traffic or similar warning signs could be added on Deere Road in advance of the intersection in both directions. Perform maintenance as needed to address pavement edge drop off. The Stop sign on Peru Road could be straightened. A stop bar could be added to Peru Road. A Hidden Driveway sign could be added south of the intersection for southbound traffic. The double arrow warning sign could be replaced. The No Passing Zone pennant on Peru Road could be straightened. 16
Peru Road and South Lot Entrances This location consists of two intersections serving different purposes for the plant. The west intersection provides access to the south employee parking lot, while the east intersection provides access for trucks to and from the plant. At shift change, the west roadway sees a moderate amount of traffic exiting to travel east on Peru Road. This can have an impact on trucks trying to enter or leave the plant. The Stop sign on the west roadway (south lot entrance) appeared to be low. The Stop sign on the east roadway was knocked over. The pavement markings on each entrance roadway were worn. A black and white Left Turn Yield sign was present along Peru Road for eastbound traffic near the intersections. It was unknown whether the county had a resolution in place for the use of this specific sign. Suggested improvements to address the issues identified include: John Deere could investigate consolidating the driveways into one roadway, with the truck entrance potentially moved north. The height of the current stop sign on the south lot entrance roadway could be reviewed per MUTCD guidance and a higher Stop sign could be installed if necessary. The Stop sign for the truck entrance roadway should be reinstalled. John Deere could repaint the pavement markings on each entrance roadway. A check could be done to confirm that a resolution is in place for the Left Turn Yield regulatory sign on Peru Road. John Deere could inform truck drivers of shift change times so that traffic flows to and from the plant can be better managed. CONCLUSIONS Funding programs are available from the Iowa Department of Transportation, such as the Sign Replacement Program for Cities and Counties (SRPFCC, http://www.iowadot.gov/traffic/ signreplacementprogram.htm), the Highway Safety Improvement Program Secondary (HSIP Secondary, https://iowadot.gov/traffic/sections/hsip), and the Traffic Safety Improvement Program (TSIP, http://www.iowadot.gov/tsip.htm) to assist in the application of many of the measures listed above. For example, these programs could be mechanisms used to fund basic sign additions and enhancements. The Iowa DOT also offers the Traffic Engineering Assistance Program (TEAP, https://iowadot.gov/traffic/traffic-and-safety-programs/traffic-engineeringassistance-program-teap) that provides up to 100 hours of consultant time to conduct traffic studies. The modifications and improvements suggested in this document should be considered, evaluated and reviewed as potential short- and long-term adjustments that could be 17
implemented. The suggestions in this memorandum are not a complete or comprehensive list of the options available. In some cases, suggested improvements could conflict with one another, and only one alternative should be pursued. Many of these suggested changes are low-cost modifications that can be accomplished in a rather short time frame. Others will require longer-term planning and prioritization. When any changes are made at a site, the impact of those changes should be carefully monitored through review of crash data, operational observations, and feedback from county staff. 18