Bike-mounted sensor could boost the mapping of safe cycling routes
20 comments
·May 14, 2025yunusabd
I was curious if the sensor would pick up other things like trees or other cyclist, but it seems like they accounted for that:
> We then log a sensor events [sic] if the majority of cells in the sensor frame agree to the same value within a threshold parameter [...]. This ensures that sensor events are only logged when large objects like cars block the sensor’s field-of-view , i.e., one or more small objects like branches or distance pedestrians in the sensor’s field-of-view will not trigger this condition. While there is no guarantee that this approach strictly identifies cars, we empirically saw during testing that passing cyclists and pedestrians rarely satisfied this condition at the typical passing distance due to the wide field-of-view of the VL53L8.
Also interesting that it's quite cheap to build:
> The whole system can cost less than $25 [...]
From the paper https://dl.acm.org/doi/10.1145/3706598.3713325
pj_mukh
So if I’m in a protected bike lane with a row of parked cars to my left wouldn’t it be flagging every parked car as a potential hazard?
ben-schaaf
Unless there's enough distance to the bike lane every parked car in a row of parked cars is a potential hazard. It's even got it's own name: dooring.
fwipsy
I assumed it could tell whether the car was passing you or vice versa.
davidhyde
From the photos, there appears to be more than one sensor on the device which may be used to tell which direction the large object is coming from. Unless you were cycling backwards or mounted the device the wrong way around you shouldn't have any stationary cars passing you. Just a guess though.
jwagenet
I don’t know Seattle so I’d be curious to know if the proximity and accident hotspots are also high traffic zones in general, whether they have a bike like (and how it’s placed), and if the routes are even bike routes or just routes that riders comfortable jostling in traffic like me took. Comfortable riders may also skew the data by being willing to “lane split” at red lights to pass stopped cars rather than waiting at the back in lane.
Having biked a lot in SF, my impression is the best protected bike lanes are on wide roads like Folsom/Howard, Fell/Oak, etc. where proximity isn’t generally an issue, but I’d expect intersections to be riskier due to higher car speeds. While cars passing on isn’t an issue on the Wiggle with a critical mass of riders, on neighborhood streets where sharing the road is obligated the drivers can be scariest, especially in the Sunset. In NYC, an abundance of one lane, one way streets make controlling an entire street easier.
The reality of city design at the moment is almost any bike route will require the sharing the road with cars at some point, usually at the start and end of a ride, because bike lane and “bike route” coverage is often poor in residential areas and business districts.
micromacrofoot
I am willing to give it a good try even if it's never perfect!
I live in a major city and the increased traffic from scooters almost feels like it could support a separate lane even if bikes didn't exist
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mhalle
This device would also be useful in places with street-side bike lanes or no bike lanes at all, to see how closely bicyclists ride next to parked cars.
Dooring remains one of the greatest threats to bicyclist safety in many locations. Even places with great bike infrastructure often have streets with parking where cyclists must ride.
pedalpete
As a long-time cyclist and former bike courier, I think most of the proximity concerns are probably of my own doing. I wonder if the device somehow accounts for this.
My initial reaction is that an accelerometer might be a better data-point, or combining this with accelerometer data.
I'm working on the assumption that a smoother path means I am interacting less with traffic or other hazards.
pimlottc
I’m not sure how much that matters. You won’t need to initiate close passes as often on a safer street.
gpm
Given a choice between a street where the cars are stuck in 2km/hr traffic and I'm passing them with a less than foot (0.3m) gap, or a street with 70km/hr traffic where they're passing me with a 1 meter (3 foot) gap... the former feels a lot safer.
Admittedly these streets aren't usually close together (either in time or space), but I've certainly biked on both.
Still, imperfect data can be better than no data.
analog31
I wonder if this can be predicted by a heat map of car crashes in your area. This is based on my private hunch that car crashes are a predictor of bike crashes. After all, if a car can crash into another car, or a stationary object such as a tree or a building, then it can crash into another bike. And the causes may be similar: Speed and inattention.
On such a map for my locale, the most crash-prone roads are exactly the ones that I instinctively avoid.
aerophilic
Just to plug a friend… Velo.ai does similar things… but has other stuff going on: https://www.velo.ai/
Interesting to see how these two would compare, but my first (light) glance points to velo.ai being further along…
kjkjadksj
Safe cycling routes are misunderstood. The best thing is taking the lane so you are actually visible. If you take the lane, most streets become very safe and mundane in my experience. Four lane roads are even better than two lane because people can easily merge around you, you can stay out of dooring range and be very visible to traffic. On two lane roads people tend to get a little angry if you take the lane, although that is what you absolutely must do because the alternative is riding in the door zone and people squeezing you passing in the same lane.
stevage
In my area there has been a program for years where you can sign up to mount a device like this to your bike for pretty much this exact same purpose. From memory it goes behind your seatpost thougho which seems less annoying.
newsclues
Needs Strava integration
There are a number of commercial solutions in this space. It's weird when there's a press release like this that acts like their solution is completely novel and unrelated to anything else.
Roadio has front and rear facing cameras with AI driven object detection to help keep cyclists and motor scooter riders safer.
https://www.roadio.com
Garmin (amongst others) has had a rear mounted radar (and bike light) system for a while. They also have one with a camera built in.
https://www.garmin.com/en-US/p/698001/
https://www.garmin.com/en-US/p/721258/