The benefits — and dangers — of crowdsourcing bike routes

Andrew Zaleski Features, Issue 4 1 Comment

Lancaster Avenue, where it reaches Wayne, Pa., seven miles from the northwest border of Philadelphia, is a four-lane thoroughfare hectic with fast-moving cars and trucks. It’s not exactly a street prime for cycling. But Rich Kerr remembers two years ago when he saw this stretch of Lancaster marked as “bike friendly” on Google Maps. “It’s the worst road you could imagine,” says Kerr, a retired New Jersey Transit engineer.

For Delaware County cyclists, however, dangerous routes are oftentimes their only option. Heavily trafficked roads with no shoulder are a standard sight throughout the county, and sometimes prove fatal. When Upper Darby resident and Haverford College professor Russell Garrett was struck by a car from behind in July 2010 — a hit resulting in head injuries that killed him later the same day — he was cycling in the westbound lane of Route 3. Otherwise known as West Chester Pike, Route 3 isn’t the safest road for cyclists, but many in Delaware County use it because they aren’t aware of an east-west alternative.

While not a regular cyclist himself, Kerr noticed the problem and decided to start finding and demarcating safe bike routes in Delaware County. He began with his home of Haverford Township. Using a model called the Bicycle Level of Service — employed by state highway administrations and municipal departments across the U.S., including in Baltimore, Houston and Philadelphia — Kerr evaluated all major roads in the township for their bicycling suitability. He bolstered his calculations with traffic figures from the Pennsylvania Department of Transportation, images from Google Earth, and on-the-ground assessments made by driving around.

Google added bicycle routes, and the ability for people to suggest their own routes, to its mapping function in 2010. As a result, Kerr was able to make his findings available to the public, something virtually anyone with their own data and a rudimentary understanding of Google Map Maker can do. But for Kerr, this method of essentially crowdsourcing bike routes can be a blessing and a curse.

“It’s kind of like Wikipedia,” Kerr says. “Anybody can get in there and mess things up and change things.”

When it comes to infrastructure, though, the stakes are a bit higher than a misleading fact on the Free Encyclopedia. Bad information could lead to cyclists putting their lives at risk, unnecessarily, on dangerous roads. So who decides what makes a functional cycling route, let alone one that is safe?

Much like Wikipedia page moderators, trusted Google reviewers must approve all routes added to Google Maps. But any assessment of the safety and convenience of cycling routes, according to John Boyle, research director for the Bicycle Coalition of Greater Philadelphia, is “totally subjective, and it does need to be vetted.”

In May, the Coalition tried its own hand at the vetting process. During a “Mapathon” hosted by Bike Delaware County, one of the Coalition’s three suburban committees, volunteers spent about two hours at Haverford College anonymously adding routes to an alternative mapping program called WikiMapping. Attendees brought their laptops and, in real time on a large digital map, overlaid walking and cycling routes for roughly half of Delaware County.

“We’re going through this right now and we’re trying to finalize the routes we want to transfer onto Google Maps,” Boyle says.

While Kerr did not use WikiMapping in his independent analysis, he did rely on a buffer layer between analyzing routes and adding them to Google Maps. After conducting his survey of Haverford Township’s roads, each received a letter grade from A through F. Per the Bicycle Level of Service method, each grade responds to a combination of factors such as lane widths, striping, traffic volume, surface conditions and on-street parking.

But even this approach can result in designating a road as safe for cyclists when, in reality, it’s not. As thorough as they are, the calculations can’t take into account every geographical factor that cyclists experience on the ground.

“Take two roads with the same width, speed limit and amount of traffic,” Kerr says. “One could be a straight road in Kansas and another could be a twisty road in Chester County with blind curves and guardrails. Mathematically they might get the same score, but someone who knows the roads might know the difference.”

“It’s kind of like Wikipedia. Anybody can get in there and mess things up.”

That’s the tricky part in evaluating safe roads, as well as some of the danger in crowdsourcing routes through a tool like Google Maps. Even with a measured, knowledgeable analysis of potential cycling routes, it’s entirely possible that relatively few safe routes exist in a place like Delaware County.

“The frustrating part about road-riding in Delaware County is that the great roads to ride in the western part of the county are dangerous to get to from the eastern part of the county,” says Mike Madonna, a Haverford contractor and 15-year cyclist. Madonna doesn’t use Google Maps to determine his routes, instead relying on the advice of friends and fellow cyclists in the Delaware Valley Bike Club.

“It’s not just that the major routes that connect towns are unsafe,” Madonna says. “It’s that there aren’t safe side-road alternatives for a good part of the county.”

In other words, any Google Map of bike routes in Delaware County must be especially attentive to each and every road. Kerr enlisted the help of a local committee of cyclists and residents to pore over his computer-generated results of Haverford Township. With local knowledge of the road system at hand, Kerr was able to define the letter grades in more detail. A road with an “A” grade, for instance, is safe for everyone’s use, while a road with a “C” grade might be safe for adults but suitable for teenagers and children only with adult supervision.

Since Kerr’s initial analysis, he’s taken to employing what engineers and planning types call the “low-stress” model. In short, a low-stress road for cyclists is one where they won’t encounter much traffic or difficulty riding. (Think of the Philadelphia area’s minor roads, with fewer cars and lower speed limits, that run parallel to its major roads.) In Upper Darby, Springfield, Lower Merion, and much of the rest of eastern Delaware County, Kerr and his team have identified low-stress roads ideal for biking.

The above data — letter grades, low-stress calculations and all — informs which routes Kerr will plug into Google Maps for public consumption. “In eastern Delaware County, we’ve researched the roads and looked at them carefully and picked the very best prospects,” he says. “It’s the best we can do in the suburbs.”

Design by Hannah Candelaria

Comments 1

  1. Speaking of one crowdsourcing project in the region, CyclePhilly, I think underrepresentation is a huge danger. I live in New Jersey and submit my tracks all the time, but though I believe I’m one of the only users of the app, I am definitely not the only person who cycles in South Jersey. But this app delivers its data right to the DVRPC, which will miss out on New Jersey information if it only goes by CyclePhilly data.

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