April 6, 1998

Commissioner of Transportation

As approved by City Council for traffic calming measures.

Recommendations:

1) That speed humps be included in the evaluation of measures to be used for future traffic calming within the context of the Traffic Calming Policy.

2) That when speed humps are selected as the traffic calming measure for a neighbourhood, they be installed in accordance to the stipulations of the Traffic Calming Policy, as well as the design and technical criteria described in this report.

3) That staff report back with any amendments that will be necessary, to conform with uniform standards and policies, as these are developed on a City-wide basis.

4) That, through Councillors Feldman and Moscoe offices, staff contact the Torresdale Avenue residents traffic committee to initiate a review of the benefits of installing speed humps on Torresdale Avenue.

Council Reference/Background/History:

Councillors Feldman and Moscoe have requested that this department submit a report to the North York Community Council, outlining how speed humps can be introduced as traffic calming measures in North York, and specifically addressing their possible installation on Torresdale Avenue.

At its meeting of February 18, 1998, North York Community Council discussed at length the matter of vertical changes to the pavement as a traffic calming measure.

During the debate there was some confusion regarding the difference between speed bumps and speed humps and the fact that until that time, vertical changes to the pavement had not been included as a possible traffic calming measure.

Staff of this department have been monitoring the installation of test sites in other jurisdictions, particularly those with similar weather environments to determine the adequacy of installing speed humps on public roads. These devices have been in use in many jurisdictions throughout the world, however, the most recent experience within municipalities that have similar weather conditions is that of the former City of Toronto which, late in 1997, approved the installation of speed humps on local streets subject to some stringent criteria. Other jurisdictions, such as Ottawa, have initiated the evaluation of speed humps on local streets after significant testing of the devices off-street.

In reviewing the experience of the other jurisdictions, it becomes apparent that an important aspect of all speed hump installations, is the need to comply with the technical guidelines and sound engineering standards which were established by the expert practitioners in this field, after significant research. Devices that are installed haphazardly, which incorporate poor design, improper coordination with roadway geometrics, or a poor choice of construction materials, do not achieve the intended speed reduction objectives but more importantly, could create unsafe road conditions.

The jurisdictions which have started to install these devices, have also started to gather information and operating experience which can now be used in the evaluation of these devices .

Discussion:

It is first necessary to clarify the difference between speed bumps and speed humps. While the installation of either type of device has as its prime objective to reduce vehicular speeds through a vertical deviation of the pavement, the impact of their installation is markedly different. This is shown in attached Figure 1.

Speed bumps are generally 7.5 to 10 cm in height, and are 0.2 to 0.4 m in width. They result in a sharp vertical movement of a vehicle travelling at slow speeds, which promotes the further reduction of the vehicle's speed to, generally, around 10 km/h. However at higher speeds, the suspension of a vehicle can generally absorb the sudden jolt before the vehicle's body can react. Experience in other jurisdictions has also indicated that street maintenance (snow removal, sweeping, etc.) can be difficult and for this reason, these devices are found principally on private property (roads and parking lots) or in some public laneways.

Speed humps also have a typical height of 7.5 to 10 cm, but their width is approximately 4 m. One of the principal elements of a speed hump is the design of the cross-section which takes the form of a sinusoidal curve, shaped as a "wave" as indicated in attached Figure 2. Such a device also has a marked effect on vehicular speed, and while the impact is less abrupt on vehicles and their occupants, it is also felt at higher speeds.

For aesthetic reasons and the eventual deformation -over time- of asphalt humps, some jurisdictions install flat-topped humps, using a mix of asphalt and interlocking brick, as shown in attached Figure 3. The cost of an asphalt speed hump generally varies between $1500 and $2000. The cost of flat-topped humps is dependent upon the extent of work required to place the interlocking brick.

The existing Traffic Calming Policy establishes a process that allows the affected neighbourhood to actively participate in the evaluation of traffic calming measures which will affect their streets. This process ensures that the approval of any traffic calming initiative is derived through community input and consensus building. The successful results of this process are apparent in the various traffic calming measures which have been installed throughout North York. Traffic circles, raised medians, pavement narrowings and gateways, are amongst the measures which were selected by residents, tested and eventually installed as permanent features.

Speed humps should therefore be included in this process so that they are designed and placed in accordance with standards that ensure that the devices achieve the objectives sought by the community in a safe and efficient manner.

As with any traffic calming device, there are several technical aspects that will govern the feasibility of installing speed humps at particular locations. For example, speed humps are generally not installed on roads that have transit routes operating on them, where the number of travelled lanes is more than two, where the traffic volume exceeds 8000 vehicles per day, or where the gradient of the road exceeds 5%. These criteria, and any others of a more detailed or local nature, should be included in the assessment of speed humps as the appropriate traffic calming devices for a particular location.

The research that has been conducted on the installation of speed humps, has concluded that generally, a safe crossing speed over the devices is around 30 kph. In the former City of Toronto, the posted speed for streets on which speed humps would be installed, might be set at 30 kph. A reduction of the speed limit to less than 40 kph, generally requires a special Bill and approval by the Province. In other jurisdiction, however, the speed limit has been reduced to an appropriate level, and advisory signs and tabs located at strategic locations to alert drivers. The latter would appear to be the most appropriate course of action for North York, whereby the speed limit is reduced to 40 kph on those sections of streets in which traffic calming has been instituted, and warning signs are installed to alert drivers to the presence of the devices.

Concerns with the installation of traffic calming, and particularly speed humps, have been expressed by emergency services within most jurisdictions. The concerns relate to potential delays in response time and the jarring of personnel, victims and material in emergency vehicles. Tests in many jurisdictions, determined that crossings at speeds of up to 30 kph, over properly designed and constructed speed humps, were accepted by drivers of emergency vehicles.

Response times are unavoidably increased by the reduction of speed in the sections of roadway with speed humps, however, this impact must be evaluated in the context of the entire trip. While speed humps would be installed exclusively on residential streets, it will be essential to evaluate their installation with staff of the emergency services to ensure that these installations do not affect streets which are considered to be primary emergency vehicle access routes.

The concerns of the residents of Torresdale Avenue with regards to speeding vehicles, were addressed by a community traffic committee which, in consultation with staff and the then local Councillor, developed a number of options. One of the options, a narrowing of the road, was tested for some time. Unfortunately, the winding nature of the road created a number of locations where the sight lines of drivers were impaired and made the installation of other traffic measures difficult. The majority of residents requested that the tested traffic calming measures not be made permanent.

As a result of the above, the speeding traffic problem has not been resolved and the concern expressed by residents remains. It is the opinion of staff, that speed humps should be tested as they can be installed without the sight lines problems experienced in the previous tests. The residents traffic committee should be reactivated to address this matter.

Conclusions:

Significant research has been conducted in many jurisdictions throughout the world, to determine the effectiveness of speed humps as traffic calming devices. More recently, tests and research were conducted in jurisdictions with weather conditions similar to those of North York, which provided significant input to address the concerns of the impact on traffic flow and roadway maintenance during the winter. These tests have also concluded that to successfully implement a traffic calming program which includes the installation of speed humps, these devices must be considered for locations where the technical conditions set for their installation will be met, where adopted guidelines for community involvement in the context of an overall traffic management review are complied and, where it is concluded collectively, that the objective of speed reduction through a residential community cannot be achieved by alternative and less restrictive traffic calming or traffic control measures.

Speed humps have the potential to address the concerns expressed by residents of Torresdale Avenue regarding speeding traffic, and their traffic committee should be requested to review this matter with staff.

Contact Name:

Roberto Stopnicki, Works and Emergency Services, Transportation, North York

Phone: 395-7480

Jim Kinrade

Commissioner

g:\managemt\humpsrep.wpd