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Home My WebLink AboutItem 4.04 Speed Feedback Demo Accptor 19 82 /ii � 111 DATE: TO: FROM: SUBJECT STAFF REPORT CITY COUNCIL June 5, 2012 Honorable Mayor and City Councilmembers CITY CLERK File #600 -35 Joni Pattillo City Manager""' Acceptance of Work — Contract No. 11 -01, Speed Feedback Demonstration Project (CIP No. 960024) Prepared by Jaimee Bourgeois, Transportation & Operations Manager EXECUTIVE SUMMARY: The Speed Feedback Demonstration Project (CIP No. 960024) procured six speed feedback signs and associated data collection software and installed the signs throughout the City at locations approved by the City Council on December 21, 2010. The project was funded by Gas Tax funds. The work is complete and ready for City Council acceptance. FINANCIAL IMPACT: The total project budget for CIP 960024 was $59,415, which was funded by Gas Tax Funds. The total costs included design, procurement of the signs, and installation. The work, including the procurement and installation of six speed feedback signs, is now complete. The total project cost was $58,126.90, as shown below. Project Element Budget Amount Actual Cost (Gas Tax) Design /Inspection /Admin $ 5,940.00 $ 1,688.31 Improvements 53,475.00 56,438.59 Total $59,415.00 $58,126.90 RECOMMENDATION: Staff recommends that the City Council accept the improvements performed under the Speed Feedback Demonstration Project. .. . Submit ed By Public Works Director Submitted By Administrative Services Director Reviewed by Assistant City Manager Page 1 of 2 ITEM NO. 4.4 DESCRIPTION: On December 15, 2009, the Dublin City Council reviewed the current process which staff undergoes to respond to residents' requests regarding traffic safety and compared it to the processes employed at various neighboring agencies. It was decided that staff would continue with the current process. A specific enhancement to the existing program identified by staff was the implementation of a speed feedback sign pilot program that would test the effectiveness of speed feedback signs as a means of attempting to reduce vehicle speeds. The City Council supported staff's recommendation and directed staff to create a new CIP project. On June 22, 2010, the City Council approved the Five -Year Capital Improvement Program (CIP) for Fiscal Years 2010 -2015, which included the Speed Feedback Demonstration Project (CIP No. 960024). On December 21, 2010, the City Council approved the locations for installation of six signs. The locations included: • Westbound Amador Valley Boulevard, east of Brighton Drive • Westbound South Dublin Ranch Drive, east of Woodshire Lane • Westbound Antone Way, east of Grafton Drive • Westbound Central Parkway, east of Aspen Street • Eastbound Dublin Boulevard, west of Brigadoon Way • Southbound Vomac Road, north of Millbrook Avenue It should be noted that, due to field constraints, the location of the Antone Way sign was moved to the opposite side (eastbound facing) of the street (Attachment 1). Sign procurement occurred in Fiscal Year 2010 -2011, and installation was completed in Fiscal Year 2011 -2012. Staff has reviewed the work and determined the work is complete. A "before and after' study was completed to identify the effectiveness of the signs. Travel speeds before speed display sign activation, immediately following speed display sign activation and over the 7 month period following display activation were compared. Generally, the study results demonstrated measurable effectiveness. Overall, there was an approximate 5% reduction in critical and average speeds during the initial week after the speed feedback signs were installed. Over the following 7 month period, the effectiveness declined slightly, leveling off at about a 4% reduction compared to before the display activation. It was expected the speed reductions would decrease somewhat over time as drivers become acclimated to the sign. The full report is included as an attachment (Attachment 2). NOTICING REQUIREMENTS /PUBLIC OUTREACH: Public noticing is not required. A copy of the Staff Report was provided to the contractor. ATTACHMENTS: 1. Final Location Map 2. Memorandum Regarding Effect of Radar Feedback Signs on Driving Speeds Page 2 of 2 Public Works Department TECHNICAL MEMORANDUM DATE: May 13, 2012 TO: Jaimee Bourgeois, Transportation & Operations Manager FROM: William Lai, Public Works Technician SUBJECT: Effect of Radar Feedback Signs on Driving Speeds Background At a meeting on March 1s`, 2011, City Council approved the purchase and installation of six radar feedback signs throughout the City. These signs were installed at the locations shown on the attached map in September 2011. This before and after study aims to analyze the effects of the radar feedback signs on driving speeds. Methodology The radar feedback sign displays were not turned on immediately after installation. Instead, only the data collection system was activated. This system recorded the volume and speed data of traffic over 12 mph (vehicles traveling slower than 12 mph are assumed to be bicyclists and are not part of this study). Data was recorded for one week (displays off), the following week (displays on), and continuously for the following 7 months (displays on) following installation. Specifically, average speed and critical speed was compared'. One note to make is that the Central Parkway sign is located near Dougherty Elementary School and is subject to two different posted speed limits depending on the time of the day. The normal speed limit is 35 mph and the speed limit immediately before and after school is 25 mph. The speed signs were programmed to reflect this. Data for both before and after was limited to the same time period of the week (Friday to Thursday) to ensure an accurate comparison. Results All six sign locations showed an initial reduction in speeds with the exception of the critical speed on Amador Valley Blvd, which remained the same. During both of the first two data collection periods, the display sign was obstructed from view by low hanging trees with a sight distance of approximately 30 feet. This would help explain why this location had the lowest reduction in average speed during the initial data collection period. During the final data collection period, the obstructing trees had been trimmed back, increasing the sight distance, and a reduction in average speed was measured. The greatest reduction in speed occurred on Antone Way as nearly 10% reduction in critical and 9% average speed was seen during the initial data collection period. While speeds did rebound slightly 7 1 Critical speed is the speed at which a majority (85 %) of motorists travel at or below. months after the installation of the signs, a sustained reduction of 7.7% in critical and 6.0% in average speed was seen. The other four locations showed initial reductions of critical speed in the range of 2.9% - 6.1% and average speed in the range of 3.2% - 5.3 %. A table of the data is attached for reference. Note: 1. Central Parkway location has a 25 mph posted speed when children are present, but data was compared during non - school hours when the legal speed limit was 35 mph. Posted Speed Limit (mph) Critical Speed (mph) Reduction Average Speed (mph) Reduction in Average Speed in Critical Speed Amador Valley Blvd (Sept -2011: `Before ") 30 32 - 27.3 - Amador Valley Blvd (Sept -2011: "After ") 30 32 0.0% 26.9 1.5% Amador Valley Blvd (April -2012) 30 32 0.0% 26.2 4.1% Antone Way (Sept -2011: `Before ") 25 29 - 20 - Antone Way (Sept -2011: "After ") 25 26 10.3% 18.2 9.0% Antone Way (April -2012) 25 27 7.7% 18.9 6.0% Dublin Blvd. (Sept -2011: `Before ") 40 49 - 41.1 - Dublin Blvd. (Sept -2011: "After ") 40 46 6.1% 39.4 4.1% Dublin Blvd. (April -2012) 40 46 6.1% 39.4 4.1% Central Parkway (Sept -2011: `Before ") 351 34 - 28.1 - Central Parkway (Sept -2011: "After ") 351 33 2.9% 27 3.9% Central Parkway (April -2012) 351 33 2.9% 27.2 3.2% S. Dublin Ranch Dr. (Sept -2011: `Before ") 25 31 - 24.3 - S. Dublin Ranch Dr. (Sept -2011: "After ") 25 29 6.5% 23 5.3% S. Dublin Ranch Dr. (April -2012) 25 30 3.2% 23.4 3.7% Vomac Dr. (Sept -2011: `Before ") 25 27 - 19 - Vomac Dr. (Sept -2011: "After ") 25 26 3.7% 18.1 4.7% Vomac Dr. (April -2012) 25 26 3.7% 18.9 0.5% Overall change (Speed Display on vs. off) 4.9% 4.8% Overall change (Next continuous 7 months) 3.9% 3.6% Note: 1. Central Parkway location has a 25 mph posted speed when children are present, but data was compared during non - school hours when the legal speed limit was 35 mph. Conclusion Overall, there was an approximately 5% reduction in critical and average speeds during the initial week after the speed feedback signs were installed. A 3.9% and 3.6% sustained reduction in critical and average speed, respectively, was seen in the seven months that followed. It was expected the speed reductions would decrease somewhat over time as drivers become acclimated to the sign. There was also variability in the percentage of speed reductions throughout the different locations which can be seen when comparing the Amador Valley Blvd. and Antone Way locations. While differences in driving habits contribute to some variability in results, environmental factors should be taken into account as well. The obstructed visibility at the Amador Valley Blvd. location contributed to the relatively small reduction in speeds during the first week of display operation. Once the obstruction was removed, a greater reduction in average speeds was seen over the following seven months, which does not correlate with the general trend of smaller speed reductions over time as drivers became acclimated to the sign. G:ACIP\Speed Feedback Signs \Tech memo radar feedback sign study.doc