Since Arlington County launched its bicycle and pedestrian counter program in 2009, Transportation Planner David Patton has been keeping the counters running. From a computer dashboard back at the office, he monitors their status and can tell when one requires hands-on attention in the field. Counters may stop working because of insect infestations and need to be cleaned out and sprayed; others succumb to a quick hit from a construction vehicle; others simply need a battery change. Most problems are routine, and Patton makes the repairs himself or uses a County contractor if specialized help is needed.

Arlington has 32 permanently installed counters. Twenty are located on busy bridges and trails, and count and classify bicyclists and pedestrians separately. Twelve more are installed in bike lanes and count only bicyclists. The County also owns six portable counters used on sidewalks and for short-term or special studies.

Identifying Active Transportation Patterns

Having been the counters’ steward for over a decade, Patton finds the data they generate fascinating and enlightening.

“It’s like seeing a pulse . . .a record of daily life,” he says, “with regular patterns of people biking to work, exercising, and going to school, day after day. We can see seasonal differences, or when it rained, or when dog walkers and runners were out. The patterns become unmistakable.”

Counter data helps planners identify peak travel times for different trails and prioritize the most heavily used locations. It also informs decision making, such as the need for maintenance and safety improvements.

Arlington’s most popular trails—Washington & Old Dominion, Bluemont Connector, Four Mile Run, and Mount Vernon—are all monitored, as well as the major Potomac River crossings.

Patton notes that different sections of a trail can have very different use patterns. This is notable, for example, where the W&OD Trail intersects the Custis Trail in Bon Air Park. Here, there is a distinct bike commuting wave in the morning, headed east on the W&OD from Falls Church and turning left onto the Custis headed toward Rosslyn. The reverse movement takes place in the afternoon, like a tide. The other leg of the W&OD, continuing southeast to Shirlington, is busier in the middle of the day, suggesting that trail users are out for an afternoon walk or other recreational activity. This section is not usually as busy during traditional commuting hours as the W&OD to Custis link.

Unsurprisingly, during pandemic lockdown conditions beginning in 2020, Patton says typical bike commuting patterns “fell off a cliff,” but data reflected that the trails were being used in new ways by people taking different personal journeys.

“We started to see big peaks of activity around 3 and 4 o’clock in the afternoon, when people probably needed a break from Zoom and Teams meetings,” he says. He adds that although bike commuting volumes haven’t returned to pre-COVID levels, the counters have begun registering noticeable increases and a return to recognizable morning and evening peak volumes.

Accessing the Counter Dashboard

The Bicycle and Pedestrian Counter Dashboard is publicly available for all who wish to explore and monitor Arlington’s bicycling and pedestrian activity. All data of bicycle and pedestrian traffic is anonymous—a blip of movement captured by the counter’s infrared lens or in-ground detector.

Arlington’s counter data is also available on a web dashboard serving the National Park Service’s National Capital Region Trail Monitoring and Analysis Program. The dashboard offers an engaging picture of bicycle and pedestrian travel patterns across the region.

To view Arlington’s bicycle and pedestrian counter dashboard, click here.