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ADMINISTRATIVE REPORT
Date: February 17, 1998
Author/Local:L.LaClaire/6440
Dept. File No. 3503-1
CC File No. 5757
TO:
Standing Committee on Transportation and Traffic
FROM:
General Manager of Engineering Services
SUBJECT:
Speed Hump Pilot Project
RECOMMENDATION
A.THAT speed humps be installed on a trial basis on 3 street segments, in one area infill, and as a component of one neighbourhood traffic plan as listed in Appendix A, if supported by local residents, at an estimated capital cost of $77,000 to be funded from the Streets Basic Capital Unappropriated Account #13/32/9801/999 (traffic calming).
B.THAT $2,800 for maintenance of the trial speed humps be approved as an increase to the Traffic Operations Budget without offset, to be reduced by $100 for each hump that is not made permanent.
C. THAT staff monitor the speed hump trial installations and report back.
D.THAT staff report back on the suitability of speed humps for 59th Avenue after the installation of the new traffic signal at Cambie and after the conclusion of the Speed Hump Trial Project.
Council has a long standing policy of protecting residential neighbourhoods from intrusion of non-local traffic on local streets.
On May 27, 1997, Council approved the Vancouver Transportation Plan which emphasizes the need to mitigate the effects of traffic on local neighbourhood streets.
On December 9, 1997, Council adopted the Transportation Plan - Report Back. This report identified the following three key action items: reduce speed limits on residential streets to 40 km/h, initiate new public processes for traffic calming projects based on priority of needs across the city, and expand the City’s traffic calming program to include a greater range of measures.
It is a Council Policy to implement traffic calming measures on a trial basis, with follow up survey, before making the measures permanent.
The purpose of this report is to seek approval and funding for the construction of speed humps on selected neighbourhood streets on a trial basis, as detailed in this report.
Residents concerned with high speed traffic on residential streets have often requested that speed bumps be installed on their streets. The City of Vancouver’s first speed humps were installed in the seventies on the East 3400 to 3600 blocks of Kent Avenue North to discourage drag racing in this industrial area. These humps remain in place today. The City currently provides lane speed humps through the local improvement process. To date the City has installed more than 300 speed humps on approximately 170 lane segments. In 1996, an informal test of three speed hump designs was conducted by Engineering Services. Fifteen key stakeholders, including Ambulance, Police, Fire and Rescue, and Sanitation, tested and evaluated these speed humps. Cyclists also tested and evaluated these speed humps.
Most recently, the Institute of Transportation Engineers (ITE), Traffic Engineering and Transportation Safety Council Review Panel adopted the Recommended Practice for Guidelines for the Design and Application of Speed Humps, effective September 10, 1997. These guidelines are the basis for the recommended trials in Vancouver.
In the past, there were four main concerns with speed bumps on residential streets that have prevented their installation. Two of these concerns, involving speed bump design, were that traditional parking lot style speed bumps were not effective at high speeds and that speed bumps would create undesirable road maintenance problems. The new designs for modern speed "bumps" have now addressed these concerns. The name speed hump is used to differentiate between traditional and modern designs.
The other two main concerns were regarding the unknown impacts on emergency response times and City liability issues. These two concerns have been addressed through the experimental use of speed humps in cities around the world. Fire and Rescue Services will use the trial period to study the potential impacts of speed humps on their responses. All four of these concerns are discussed in detail in Appendix B.
North American cities currently using speed humps as a traffic calming measure include:
Fort Lauderdale and Tampa FL
Boulder CO
Bellevue and Seattle WA
Portland OR
Berkeley and Sacramento CA
Phoenix AZ
Locally, Burnaby, New Westminster, North Vancouver, Coquitlam, and Whistler have installed speed humps on neighbourhood streets. The documented experience of cities using speed humps on streets is supportive of their use. This is mainly because speed humps have been shown to be effective at reducing the average vehicle speed on streets with chronic speeding problems. Additionally, speed humps are comfortably crossed by cyclists and do not affect street parking. Some of the advantages and disadvantages of street speed humps are summarized in table 1.
Table 1: Advantages and Disadvantages of Speed Humps as a Traffic Calming Measure.
Hamilton Associates of Vancouver (ICBC study, April, 1997) found, using data collected world-wide, that the installation of speed humps reduced motor vehicle accidents by an average of 75%. This accident reduction rate is similar to the results achieved with the installation of traffic circles (82%), chicanes (82%), and road narrowing (74%).
It is proposed to conduct a pilot project on Vancouver streets before making any further recommendations regarding the use of street speed humps in Vancouver. Street design and driver behaviour can vary considerably from city to city, and the monitoring of this pilot project will assist in determining the suitability of these speed hump designs on Vancouver streets.
For the proposed City of Vancouver Pilot Project, the evaluation model and selection criteria are based on the Portland, Oregon speed hump ranking program. The model was modified to reflect conditions in Vancouver and includes factors such as existing traffic speeds and volumes, pedestrian facilities and generators, and proximity to schools, greenways, and bikeways. A sample evaluation of a Vancouver street segment is detailed in Appendix E. The prioritization and ranking of the street segments has helped to strategically select street segments that will allow exploration of the physical and psychological effects of speed humps on traffic speeds in three settings:
1.One top ranked local street from three speed zone categories (50 km/h, time limited 30 km/h, 24 hr 30 km/h), subject to resident support, for a total of three top ranked streets.
2. One area speed hump infill, comprised of five streets of varying ranks.
3.As components of one neighbourhood traffic plan, which includes two streets of varying ranks.
The above three scenarios total ten streets that represent a broad range of conditions. A speed hump can be a severe speed control device that will likely increase maintenance costs and could likely have no benefit if applied in unwarranted locations. The above streets have been carefully selected to provide varied and useful before and after data in the context of a Pilot Project after a detailed review of 81 locations suggested by staff, the Vancouver Police, and residents. This pilot project is not a selection of all the streets that might benefit from speed humps, and it is crucial to the integrity of the Pilot Project that the scope of the project be limited as described here to allow for a controlled test of the suitability of this device for Vancouver streets.
The complete list of all ranked street segments is included in Appendix F. The good news is that, unlike Portland, the local streets in Vancouver do not, in general, experience excessively high speeds. If Portland’s warrant system were applied in Vancouver without modification, a total of only 11 of the 81 street segments would be eligible for speed hump installation.
The Vancouver speed hump pilot project will test two different speed hump designs, described below in Table 2 and illustrated in Appendix C. The 30 km/h speed hump is recommended for a trial installation in a playground zone (time limited 30 km/h) and in a 24 hour 30 km/h speed zone. The 40 km/h speed hump is recommended for trial installation on local neighbourhood streets only. One of the selected street segments is on a City Bikeway, which will provide an opportunity to assess the impact of speed humps on Bikeways and provide feedback from cyclists.
Table 2: Dimensions of Speed Humps
SPEED BUMP/HUMP LENGTH HEIGHT ENCOURAGES SPEEDS BELOW
Parking Lot Speed "Bump" 0.3 to 1.0 m 7 to 15 cm 5-10 km/h (Not effective at high speeds)
Current Lane Hump 3.7 m 10.5 cm 20 km/h
Proposed 30 km/h Hump 3.7 m 7.5 cm 30 km/h
Proposed 40 km/h Hump 4.3 m 7.5 cm 40 km/h
This Project addresses three key Transportation Plan actions items:
NP1 Reduce the speed limit on local streets to 40 km/h. The proposed speed humps will be designed for comfortable crossing at 40 km/h.
NP3Initiate a new public process for the traffic calming projects based on priority of needs across the City. Selected street segments were chosen using a point ranking system similar to Portland’s, which will assist in the establishment of a model for the ranking of other traffic calming measures and projects.
NP9 Expand the City’s traffic calming program to include a greater range of measures. If adopted, speed humps would expand the range of traffic calming measures used by the City.
On June 26 1997, Council instructed staff to report back on the applicability of installing speed humps on Larch Street, particularly around the 37th Avenue intersection. Although Larch Street is currently classified as a secondary arterial, it was considered as a potential location in response to this direction from Council. Since Larch Street in not currently classified as a local street it would not be affected by the proposed reduction in the local speed limit to 40 km/h. Larch Street has an 85th percentile speed of 54 km/h. This is the speed at which 85 percent of all vehicles are travelling below and 15 percent of vehicle are travelling above. In this location a 50 km/h speed hump would most likely have only a minor impact and is therefore not recommended at this time. However, the newly adoptedTransportation Plan proposes that Larch Street be re-designated as a collector street. It is recommended that Larch Street be monitored and re-assessed after its designation has been reviewed and after the Speed Hump Pilot has been completed.
On January 20 1998, Council approved the installation of a full traffic signal at 59th and Cambie as well as a recommendation from the General Manager of Engineering Services that further traffic calming measures on 59th Avenue be evaluated as part of the speed hump trial report and future Greenway Corridor. Staff have gathered speed and volume data for 59th Avenue in its current configuration. In terms of inclusion in the pilot project, 59th Avenue is a poor choice because the new traffic signal at Cambie will be installed shortly and may or may not affect speed and volume measurements along 59th Avenue. Introducing trial speed humps now would make the before and after data comparison of the effectiveness of speed humps inconclusive, because two significant changes to traffic controls on this street would have been made at the same time.
However, 59th Avenue currently ranks 3rd out of 21 street segments that are subject to time limited 30 km/h zones. While the speeds and volumes along 59th Avenue will need to be remeasured after the installation of the signal, 59th Avenue is likely to remain a strong candidate for consideration for speed humps. It is recommended to Council that staff report back on the suitability of speed humps for 59th Avenue after the installation of the new traffic signal and after the conclusion of the Speed Hump Trial Project, and that this information be included for Council in the report back.
The impact of street speed humps on noise levels and air polution is uncertain. However this pilot project will help assess the impact on noise levels using before and after noise data that will be gathered at the test locations and from resident surveys. Additionally, the latest research on the environmental impacts of speed humps will continue to be tracked as it comes available.
The estimated capital cost for the proposed Pilot Project is $77,000 to be funded from the Streets Basic Capital Unappropriated Account #13/32/9801/999 (traffic calming) and includes associated signs, road markings, public consultation, and gathering before and after traffic data (see Appendix D for cost details).
Speed humps that become permanent will require maintenance in the form of road markings re-painted every two to three years as well as signs and asphalt repair and replacement as needed. Also cut repair implications will be monitored. The estimated annual maintenance cost for the proposed Pilot Project is $2,800 to be added to the Traffic Operations Budget without offset.
Speed humps would be installed in Spring, 1998. Vehicle speeds, volumes, and noise levels would be measured before installation. They would be measured again, once traffic patterns and driver behaviours have stabilized, approximately six months after installation. Residents would also be surveyed before and after the trial installations to gauge the neighbourhood support for the speed humps.
A thorough analysis of the before and after measurements and surveys will help determine the effectiveness and suitability of speed humps. The results of the study and recommended conditions for the use and funding of speed humps will be detailed in this report back to Council in approximately one year.
Any speed humps that are deemed hazardous in the review or considered objectionable by a majority of neighbouring residents will be removed.
Modern speed humps are now being used on low volume streets in many cities around the world. The accumulation of data and experience from installations in these cities has provided the basis for new design standards and guidelines for the use and application of speed humps. However, street design and driver behaviour can vary considerably from city to city and speed humps have fewer advantages than other traffic calming measures. The recommended trial installation of speed humps on the ten street segments identified in this report will assist in determining the suitability of these new speed hump designs on Vancouver streets.
Table 1: Top ranked street segments in each speed zone category
Dunbar Marine Neighbourhood (40 km/h speed humps)
Table 3: Neighbourhood Plan Application
Clinton Park Neighbourhood (30 km/h speed humps in a playground zone)
Refer to Appendix F for a complete list of all street segments that were investigated.
Traditional Concerns With Speed Humps on Streets
Four main concerns with speed bumps on residential streets have prevented their installation in the past. These concerns have now been addressed by the development of new speed hump designs and with the experimental use of speed humps around the world. All four of these concerns are discussed in detail below.
1.One concern is that the traditional designs for speed "bumps" are not an effective deterrent on city streets when speeds are high. A traditional parking lot style speed "bump" is generally 0.3 m to 1.0 m long (one to three feet long) with a height of 7 cm to 15 cm (three to six inches). Speed "bumps" are less effective at high speeds because the vehicle suspension allows the wheels to travel up and over the bump while the chassis remains unperturbed. In contrast, modern speed "humps" are designed to limit specific maximum travel speeds. The proposed street speed humps would be 7.6 cm (3 inches) high at the crown and would vary in length according to the design speed. For example, a 4.3 m (14 foot) long speed hump is designed so that drivers travelling 40 km/h and less will experience minor discomfort while drivers travelling over 40 km/h will experience increasing levels of discomfort at increasing speeds. A longer 6.7 m (22 foot) speed hump could be used to encourage speeds below 50 km/h. A more severe 3.7 m (12 foot) long speed hump is used to encourage speeds below 30 km/h. Our current lane hump design is 3.7 m (12 feet) long and 10 cm (4 inches) high, encouraging speeds below 20 km/h. The various speed hump designs are shown in Appendix C.
2. Another concern is that speed humps will cause problems for road maintenance and snow clearing. Damage from snow plowing was initially a concern, however, the experiences of other cities, many which receive considerably more snow than Vancouver, such as Whistler, indicate that the humps are generally not a detriment to these activities provided that the hump edges are properly maintained. Further to this, speed humps are proposed for installation on local neighbourhood streets only. Since these streets have the lowest priority for snow clearing, snow clearing equipment will rarely encounter speed humps.
3. A third concern is that speed humps could have a negative impact on the response time for emergency vehicles. The City of Portland, Oregon, which has over 310 speed humps on city streets, recently completed a study of the effects of traffic calming measures on emergency response times. This study concluded that a 40 km/h hump results in 1.0 to 9.4 seconds of delay. The negative effects on emergency response times need to be balanced
with the benefits of traffic calming, including reduced speed, enhanced pedestrian safety, decreased vehicle accidents, and improved livability along neighbourhood streets. Additionally, speed humps are proposed for use only on local streets where there is infrequent use by emergency vehicles. It is important to note that same Portland report concluded that speed hump delays are less than those caused by traffic circles (1.3 to 10.7 seconds).
Vancouver Fire and Rescue Comments
Vancouver Fire and Rescue Services has not had an opportunity to fully evaluate the adverse effects of speed humps on emergency response times. The trial period will be used to study the potential impacts of speed humps on their responses.
Fire and Rescue Services expects that an individual speed hump would have a smaller adverse impact on emergency response times than a traffic circle at the same location. However, the cumulative effect of a series of traffic calming devices along a response route (diverters, circles, humps, etc.) could have a significant adverse effect in total. Therefore, any proposed traffic calming devices must be evaluated as part of the total design, taking into consideration alternative access routes and local target hazards.
Vancouver Fire and Rescue Services will continue to be fully involved in the evaluation and approval of all proposed installations of traffic calming devices as they relate to emergency access.
4. The final concern is that vehicles damaged or persons injured while crossing a speed hump could hold the City liable for damages. However, the experiences of other cities reveal that liability problems with the 50, 40, and 30 km/h hump designs have been minimal to non-existent. Legal problems are typically in the form of threats rather than actions. Speed humps that are appropriately painted and signed provide sufficient warning to the motorist that the speed limit must be respected. Consequently, there has been no successful litigation against a jurisdiction with regard to speed humps on neighbourhood streets of which we are aware.
Table 1: Installation costs
Table 2: Maintenance Costs
32 signs @ $ 20/sign
$ 640
(based on re-painting every 2-3 years @ $180 per hump)
$2,100
TOTAL
$2,800
Using a Modified Portland Scoring for Local Service Streets
Raw Data (measured on two separate occasions)
Sample size = 98 vehicle speeds
Average Daily Traffic (ADT) volume = 3000 ADT
85th percentile speed (calculated) = 52.2 km/h
Design speed for hump (speed limit) = 40 km/h
Speed Points (convert to imperial: speed limit 40 km/h = 25 mph,
85th percentile speed 52.2 km/h = 32.4 mph)
Assign 5 points for each mph in excess of 5 mph over the speed limit.
Volume Points (ADT/100 = 3000/100) = 30
Is the Primary Score greater than 40?
If YES, then proceed to Secondary Scoring.
(Since 42>40 proceed to Secondary Scoring.)Secondary Score
Additional Speed Points for excessive speed (based on percentage of
vehicle travelling over 16 km/h beyond the design speed of the hump
i.e. percent travelling > 40 + 16 km/h = 56km/h) : 8% = 8
Score 5 points for each school zone (maximum 10) 0
Score 5 points for each pedestrian generator (maximum 15) 10
- Count SkyTrain Station/bus loop and retail area as two ped generators
Score 5 points if adjacent to a Greenway (is part of the BC Parkway) 5
Score 5 points if the street segment is part of a Bikeway 5
Score 5 points if the street segment lacks a continuous sidewalk 5
TOTAL SCORE (Primary + Secondary) = 75
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