How can you use speed humps to improve traffic safety on residential streets?

1 Benefits of speed humps

Speed humps have several benefits for residents, drivers, pedestrians, and cyclists. They can reduce the average speed of vehicles by 10 to 15 km/h and the 85th percentile speed by 20 to 30 km/h. This means that most drivers will comply with the posted speed limit or lower and fewer drivers will exceed it by a large margin. Lower speeds reduce the risk and severity of crashes, especially for vulnerable road users like children and seniors. Speed humps can also discourage drivers from using residential streets as shortcuts, resulting in less traffic volume and congestion. Additionally, speed humps can lower the noise and air pollution levels on residential streets by preventing acceleration and braking cycles.

2 Design of speed humps

Speed humps are not the same as speed bumps, which are smaller and sharper and typically used in parking lots and private driveways. Speed humps are designed to be gentle enough for drivers to cross at a reasonable speed without damaging their vehicles or causing discomfort. The standard dimensions of speed humps are 3 to 4 meters long, 7 to 10 centimeters high, and as wide as the travel lane. They can be circular, parabolic, or sinusoidal in shape, depending on the desired speed reduction and aesthetic preference. Speed humps should be spaced at intervals of 50 to 150 meters, depending on the street geometry and traffic characteristics. They should also be clearly marked with signs, pavement markings, and reflectors to warn drivers and avoid collisions.

3 Implementation of speed humps

Speed humps are a relatively easy and inexpensive traffic calming measure to install, maintain, and remove compared to other measures. However, careful planning and consultation with stakeholders, such as residents, emergency services, public transit, utilities, and maintenance crews is essential. Factors to consider include the existing speed and volume of traffic on the street, the presence of driveways, intersections, crosswalks, bike lanes, and bus stops, the impact on emergency response times, transit operations, drainage, snow removal, and street sweeping. Additionally, the support and approval of the majority of the residents on the street must be obtained alongside availability of funding and resources for installation and maintenance. It is worth noting that speed humps may have some drawbacks such as increased noise and vibration near the humps, potential damage to vehicles or bicycles, and possible displacement of traffic to other streets. Therefore, monitoring and evaluating the performance and effects of speed humps after installation is important in order to make adjustments if necessary.

5 Here’s what else to consider

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