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Vehicle Side Guards

We installed vehicle side guards on 18 Public Works trucks to reduce the risk of 'under-ride fatalities' to cyclists in the case of a crash.

We’re piloting side guards as a model for others. We hope to encourage those with truck fleets on our City streets to follow our lead.

Why we did this

In 2012, Boston experienced five bicycle fatalities, four of which occurred with either a large truck or a bus.

The City worked with Dr. Alex Epstein and his team from the U.S. Department of Transportation Volpe Center in Cambridge. We researched best practices regarding large vehicles and the more vulnerable users of the roadways.

One solution we identified was side guards. What are side guards? Rails or flat-surfaces mounted between or in front of the wheels on large trucks. They help prevent cyclists and pedestrians from crashes involving sliding under the rear tires of the vehicle. This is a design modification used throughout:

  • Europe and Japan, and
  • in select US and Canadian cities.

In fact, a national law made side guards mandatory in the United Kingdom. One study showed deaths of cyclists who collided with trucks decreased by 61 percent. To request an inspection of side guards, please visit the Inspectional Services truck safety page

The experiment

Our hypothesis? Adding side guards to some of the City’s trucks will improve the safety of cyclists on the road. It will also encourage other City truck operators to make similar investments.

Public Works retro-fitted 18 trucks with large wheelbases using resources from the Streetscape Innovation Fund. The truck models years were 2005 or later and included:

  • some dump trucks
  • box trucks, and
  • trash collection vehicles.

This is believed to be the largest pilot of side guards on municipal vehicles in the country. Side guards are also now standard on all large vehicles added to the City fleet and City-contracted vehicles.

Results and lessons learned

Getting others involved

Since the initial pilot, over a hundred vehicles in Boston have been outfitted with side guards as part of the ordinance passed by the City in 2015 that requires City-owned vehicles and contractors of the City to outfit their trucks with guards, mirrors, and safety decals. Private fleet managers have attended a demonstration on side guards and the cities of Cambridge and Somerville have adopted similar policies.

New requirement for vendors

In spring 2014, the City required waste hauling vendors with City contracts to install side guards on their trucks. In 2015, the project was extended to include all vendors. Currently the City is working with state legislators on adopting the technology for all trucks in the Commonwealth. 

Saving a life

One crash with a side-guard equipped trash vehicle was reported in the summer 2014. The cyclist was injured, but the crash did not result in that person’s death.

Citywide ordinance And National Efforts

The pilot led to a citywide ordinance requiring side guards and blindspot mirrors on all large trucks holding City contracts. This started in spring 2015. The City has supported legislation filed for Commonwealth-wide adoption in the last two legislative sessions, as well as worked with USDOT and MA representatives on national requirements for sideguards. More than a dozen US cities have adopted Boston's approach in requiring these devices since our initial pilot. 

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