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Counting Bike Trips Could Get More People To Pedal

SDSU Professor Sherry Ryan poses over an electronic loop, embedded in the street, that keeps track of the number of bikes which travel on that route.
Tom Fudge
SDSU Professor Sherry Ryan poses over an electronic loop, embedded in the street, that keeps track of the number of bikes which travel on that route.
Counting Bike Trips Could Get More People To Peddle
A program to monitor bike use in San Diego County seeks a way to improve the cycling environment.

There was a light rain falling in Balboa Park where a small group of well-dressed people came to make an announcement. They found a dry place under a magnolia tree. One of them was county health officer Dean Sidelinger, who was there to talk about Bikes Count.

"With Bikes Count, San Diego now has the largest regional, interconnected automatic bicycle and pedestrian counting system in the country," he said.

People who build and maintain freeways have lots of information about how many motorists use them. But we don't know much about bike riders on city streets. Bikes Count aims to change that.


The bike-monitoring program began with a $16 million grant to the San Diego County Health Department. It paid for the installation of electronic sensors in 28 locations in San Diego County. There are monitors in 13 cities. Sixteen locations are in the City of San Diego.

Muggs Stoll, the planning director for SANDAG, said when you're building roads or bike paths, you need a little info.

"If you're running a business or creating a program,” said Stoll, “you want to know about your existing customers. Where are they? What are they doing? What are their patterns? That's what this data is all about."

One of the bike sensors is on 5th Avenue. There, a handful of bike enthusiasts rode across it for the benefit of the TV cameras. Sherry Ryan is a public affairs professor at San Diego State University, and is with SDSU's Active Transportation Research Center. She manages Bikes Count and she crunches the numbers.

"So we have a small computer basically installed in the sidewalk,” she said, describing the technology. “It's attached to an inductive loop that runs out into the asphalt. And when a cyclist goes over the loop, it triggers a count."


The bike sensors have been in place now for about three months, and they tell us a lot about bike traffic volume in San Diego. The number of daily bike trips, on a given road, can range from 25 to 2,500.

The counts also tell you something about why people are riding. For instance, one sensor in La Jolla has shown lots of traffic on the weekends. That indicates a lot of recreational cyclists. But Ryan says it's a different story at monitored locations in Vista and El Cajon.

Some cyclists approach a bike trip scanner, embedded in the street on 5th Avenue in San Diego.
Tom Fudge
Some cyclists approach a bike trip scanner, embedded in the street on 5th Avenue in San Diego.

"When look at those numbers we see peaking on a Tuesday, Wednesday and Thursday. Just based on my experience going out to those locations, mostly low-income Hispanic cyclists getting to work," she said.

Safety clearly makes a difference when it comes to motivating cyclists. The new bike data show that bike paths, which keep bikes separate from car traffic, are the most popular. Unmarked bike routes come in second, while bike lanes, which are marked with stripes of paint, come in last, probably because so many of them are on roads heavily used by cars.

Ryan's San Diego cycling profile also relies on human counters who observe bike traffic. She said their observations are pretty interesting.

"Probably about 80 to 90 percent of cyclists are men. We're provided a system that doesn't serve women. We don't feel safe. We don't feel comfortable,” said Ryan.

Another thing human counters notice is how many people ride on sidewalks, as opposed to the street. Again, it’s a sign of the strong desire of bicyclists not to share their path with cars.

“This data has to come together to support building infrastructure," said Ryan.

There is some money for that. About two percent of San Diego's Transnet tax is dedicated to walking and biking infrastructure. About $2.5 billion of SANDAG's 40-year transportation plan goes to what they call active transportation. Keep in mind that's a small portion of a plan that totals $200 billion.

Cycling enthusiast Hans Wangbichler attended the announcement of the Bikes Count project. He said he'd like to see a protected bike lane, called a cycle track, from downtown to Hillcrest… one very common trip in the central city. But where do you put it? He said the monitoring program could help answer that question.

"Maybe they put it on one of the roads and they find out, well… we're hardly getting any readings on this road. Maybe we shouldn't be putting our cycle track there," said Wangbichler.

Biking is good for the environment and good for health. But it's not always safe, and the U.S. Census has found that less than 1 percent of San Diego county commuters use it as their mode of transportation. Could investment in the right kind of roads and bike paths boost that number a bit? That's the hope.