Keeping our roads safe...

A speed hump is a 4-meter-long section of roadway, raised across the width of the road, causing a vertical deflection for vehicles passing over them. Their primary purpose is to reduce vehicle speeds. A sensation of discomfort will be sensed by the occupants of vehicles travelling at higher speeds. These measures are typically installed on local or low traffic volume collector roadways.

The specific locations selected for the installation of speed humps depend on existing site conditions. Speed humps in front of driveway openings, on curves with limited visibility, or over sewer or water infrastructure covers should be avoided. Adequate spacing of other measure is also considered to achieve the desired calming effect. They have minimal impact on drainage but they require additional caution during snow clearing operations.

A speed table is a 7-meter-long section of roadway, raised across the width of the road, causing a vertical deflection for vehicles passing over them. Unlike speed humps, a speed table has a 3-meter-long flat top section between the 2-meter-long gradual tapers. Their primary purpose is also to reduce vehicle speeds. However, their elongated design reduces the negative impacts emergency vehicles and transit buses may experience with speed humps. Speed tables are typically better suited for collector roadways.

The specific locations selected for the installation of speed tables depend on existing site conditions. Speed tables in front of driveway openings, on curves with limited visibility, or over sewer or water infrastructure covers should be avoided. Adequate spacing of other measure is also considered to achieve the desired calming effect. They have minimal impact on drainage but they require additional caution during snow clearing operations.

Like speed humps, speed cushions are 4-meter-long sections of raised roadway. However, the elevated surface is not raised across the width of the road. A single installation will typically include series of spaced out 2 to 4 speed cushions. Their primary purpose is to reduce vehicle speeds. However, the space between the cushions has been carefully designed to allows large emergency vehicles such as fire trucks or transit buses to “straddle” the measures to minimise the impacts on emergency response times and bus passenger discomfort. Passenger vehicles are unable achieve this effect due to a narrower wheel track. A vertical deflection will be unavoidable on at least one side of a passenger vehicle when speed cushions are traversed.

The specific locations selected for the installation of speed cushions depend on existing site conditions. Speed cushions in front of driveway openings, on curves with limited visibility, or over sewer or water infrastructure covers should be avoided. Adequate spacing of tother measure is also considered to achieve the desire calming effect. They have minimal impact on drainage, but they require additional caution during snow clearing operations.

A raised crosswalk is a marked crosswalks built at a higher elevation than the adjacent roadway. The purpose of the elevated crossing surface is to improve the visibility of pedestrians, and to reduce vehicle speeds by causing discomfort to the occupants of vehicles travelling at higher speeds.

The specific locations selected for the installation of raised crosswalks depend on existing site conditions. They can be applied at intersections or mid-block locations. However, locations in front of driveway openings, on curves with limited visibility, or over sewer or water infrastructure covers should be avoided. Adequate spacing of other measure and drainage is also considered to achieve the desire calming effect while maintaining adequate stormwater management. Additional caution is required during snow clearing operations.

A raised intersection is an intersection built at a higher elevation than the adjacent approach roadways. The purpose of the elevated road surface is to improve the definition of crosswalks, emphasising the pedestrian priority at the intersection, and to reduce vehicle speeds by causing discomfort to the occupants of vehicles travelling at higher speeds.

The specific locations selected for the installation of raised intersections depend on existing site conditions. They can be applied at two-way or all-way stop intersections. Adequate spacing of other measure and drainage is also considered to achieve the desire calming effect while maintaining adequate stormwater management. Additional caution is required during snow clearing operations.

Drivers perceive narrow travel lanes as less comfortable to navigate at higher speeds. As a result, intentionally reducing lane width ultimately reduces operating speeds. This effect can be achieved using pavement markings. The vehicle types and road classifications are reviewed when considering lane narrowing ensure appropriate lane widths for the manoeuverability of large vehicles (fire trucks, snow plows, buses, etc.). Often, the reclaimed space is reallocated to other road users by implementing facilities like on-street cycling lanes or parking lanes. 

Speed display devices capture vehicle speeds using radar. The measured speeds are then displayed on an electronic board to inform drivers of their speeds. Their purpose is to increase driver awareness of their operating speeds to encourage speed reductions.

Flexible delineators are seasonal installation that create a physical separation within the roadways. When present, drivers perceive the roadway to constrained, causing discomfort to the occupants of vehicles travelling at higher speeds. These devices can be applied along the centerline, along the roadside or any combination thereof. Examples would be at crosswalk locations or along on-street cycling lanes.

Traffic circle / traffic button / mini-roundabout are measures with islands in the centre of intersection. Vehicles travelling through the intersection are required to move in a counter-clockwise direction. The purpose of the lateral shift caused by centre island is to reduce vehicle speeds, discourage residential cut-through traffic, and reduce collision severity and rates. 

Here are the distinctions between mini-roundabouts, traffic circles and traffic buttons: 

• Mini-Roundabouts: Mini-roundabouts follow the same design principles as a full-sized roundabout. Typically, barrier or mountable splitter islands are installed on all approaches. 
• Traffic Circles: Traffic circles are smaller compared to mini-roundabouts and have landscaped centre islands. Typically, splitter islands are not installed on the approaches.  
• Traffic Buttons: Traffic buttons are smaller compared to traffic circles centre islands and have hardscaped and mountable centre islands. Typically, splitter islands are not installed on the approaches.  

In retrofit scenarios, the specific locations selected for the installation of mini-roundabouts, traffic circles or traffic buttons depend on existing site conditions. The space within an existing intersection, the angles of the approaches and the grades within an intersection are constraints that influence the feasibility to apply these types of measures. Maneuverability of large vehicles such as fire trucks, buses and snowplows largely influences the centre island design. Additional caution is required during snow clearing operations.