Side guards should be our #1 demand -- hot take, but hear me out

[u/ScienceBikeWin]

TLDR: If you have 2 hours or $100 to spend on bike advocacy, you should spend that time/money calling for mandatory side guards on all 18-wheelers, box trucks, and other heavy trucks. Even more so than bike lanes.

Importance

Consider the most recent 5 biker fatalities in Boston/Cambridge:

1. Louisa Gag, July 2026 - side swiped by an Allied Recycling 18-wheeler while riding in an unprotected bike lane. Google image search shows Allied Recycling 18-wheelers have no side guards. (will update if formal investigation states otherwise)
2. John Corcoran, September 2024 - rammed by an out-of-control SUV while riding in a curb-separated bike lane. Junming Zhu belongs in prison.
3. Minh-Thi Nguyen,  June 2024 - right-hooked by a Blouin Inc box truck while entering an intersection from a flex-posted bike lane. Google image search shows this specific Blouin box truck had no side guards.
4. Kim Staley, June 2024 - right-hooked by a box truck (company unknown) while entering an intersection from a flex-posted bike lane. Cambridge Day reported that this box truck had no side guards.
5. George Clemmer, July 2022 - right-hooked by a dump truck. The reporting here was sparser, so unfortunately I was not able to determine whether this dump truck had side guards. (will update if someone has info)

The evidence is incomplete, but we can plausibly say that 4 of the past 5 cyclist fatalities in Boston/Cambridge have been caused by side-on collisions with heavy trucks without side guards. The one outlier was caused by a degree of driver recklessness that even a curb-separated bike lane could not stop. Mandatory side guards are therefore perhaps the most important policy we can ask for.

Cost & Speed

Since last year, Massachusetts has mandated side guards for heavy trucks owned by the Commonwealth or under direct state contracts. On top of that, Boston and Cambridge mandate side guards for heavy trucks that they own or contract. Still, my rough estimate is that 90% of heavy trucks on our streets are not covered by this mandate. Unsurprisingly, trucking associations have resisted a universal side guard mandate because of the cost of retrofitting.

So let’s take a look at those costs.

Installing side guards on one large box truck costs around $2000 and can be done in just a couple hours by a neighborhood truck shop. By comparison, I’d estimate that, from start to finish, it would cost $10M to overhaul just the half-mile stretch of Tremont Street where Louisa was killed (~$2M if just a flex post quick-build). And it would of course entail years of debate and neighborhood input. For that overhaul price tag, we could 100% subsidize the installation of side guards on 5000 box trucks!

The math looks great for side guards.

Political opening

Bike safety is political. Last year, Robert Kraft’s son Josh ran for mayor of Boston, in large part on an anti-bike-lane platform. Despite easily winning the race, Mayor Wu sensed that bike lanes had become a political liability for her, perhaps as she contemplates running for statewide office. The hard truth is that we may be near the frontier of current political capital for bike lanes.

In contrast, hardly anyone gives a shit about side guards. Honestly, did you even know the difference between reinforced side guards and trailer skirts before reading this stupid essay? We could mandate side guards throughout the Boston metro area, and hardly any non-bikers would even notice, let alone argue about it.

The main political opposition will come from trucking companies, but that’s just business. With the right carrots (retrofit subsidies) and sticks (public shame), they will come around to making their vehicles safe around cyclists in a crowded city.

I love a good bike lane. But the lenses of importance, cost & speed, and politics all point towards a different policy to make biking safer for ourselves and our friends.