Graduate Student Learns to Count on Walk and Bike to School Day

This guest blog post was written by our research adviser, Christina Galardi.

Back to the basics: even though I’ve completed college-level mathematics courses, this month I returned to elementary school for an important lesson in my 1,2,3’s.

As a graduate student in city planning and Safe Routes to School research advisor, I know the value of having data on active transportation rates for reporting and policy/program decision-making, but I had never had the opportunity to collect the numbers myself. And so, at the request of the town transportation planner in Carrboro, NC, I willingly agreed to conduct student pedestrian and bicyclist counts at a local elementary school on International Walk and Bike to School Day, held May 6.


By 7:20 a.m., I was stationed on a street corner, clipboard in hand. The task seemed simple enough: merely tallying arrivals by bike or foot. However, the morning arrival began as a leisurely trickle of motorists, bicyclists, and pedestrians, building up with an increasingly frantic rush until the bell rang and the morning announcements carried through a few open windows. The town transportation planner, a fellow student volunteer, and I divided our efforts to cover the only two paved entrances to the school grounds, but early on we realized that a few walkers and bikers were cutting across a grassy opening behind the playground. My student peer quickly moved to monitor this location, but this could have contributed some error to our counts.

The whirlwind was over within half an hour, and we convened to total our tallies:

  • 63 bikers
  • 94 walkers
  • 157 total, which was 31.4% of the school population

According to the Carrboro Bike Coalition, 199 out of 468 students walked or biked during the 2014 event, a record 42.5% participation. The town transportation planner suggested that a telephone message from the principal the night before last year’s event boosted participation. The crossing guard also said she was not aware of this year’s event, which may indicate that word did not spread as widely this time.

But numbers were not the only findings in this case study – I made a few other key observations that verified previous scholarly research:

  • Even at my position at a three-way stop with a relatively low volume of traffic, I started to second-guess whether I had already marked bikers or walkers coming from different directions. Furthermore, other questions arose: for example, do you count a kick scooter as a biker or a walker? Accuracy is an important consideration for manual bike and pedestrian counts, no matter how simple the task may seem. A 2009 study in San Francisco found that bikers and walkers were undercounted between 8 and 25% during 15-minute intervals of manual counts in the field compared to manual counts using video footage (National Cooperative Highway Research Program, 2014).
  • Parents accompanied the majority of students who walked or biked through my intersection, either using the same mode or walking alongside a child biking. This was a reminder of the influence of parent initiative in walking and biking, sometimes by setting the example. Active transportation by parents has been positively associated with active school transportation (Van Kann et al., 2015). This observation also points to opportunities to help parents teach their children to be independently mobile and build confidence in traveling without parental accompaniment, following suggestions from Carvera (2014).
  • Parents often greeted other parents or the crossing guard, and some students chatted or played with other children walking or biking. Active transportation can promote social interaction and a stronger sense of community, which can generate health and social benefits that may not always be considered by planners and decision-makers (American Public Health Association, 2010).

It seems that you’re never too old to learn a lesson from a trip back to elementary school.


American Public Health Association. (2010). The Hidden Health Costs of Transportation. 

Carvera, A., Panterb. J., Jonesd, A., & van Sluijsb,, E. (2014). Independent mobility on the journey to school: A joint cross-sectional and prospective exploration of social and physical environmental influences. Journal of Transport & Health, 27 Jan 2014, online.

National Cooperative Highway Research Program. (2014). Guidebook on Pedestrian and Bicycle Volume Data Collection. Transportation Research Board. NCHRP Report 797.

Van Kann, D.H.H., Kremers, S.P.J, de Vries, S.I., de Vries, N.K., & Jansen, M.W.J. (2015). Parental Active Transportation Routines (PATRns) as a Moderator of the Association Between Neighborhood Characteristics and Parental Influences and Active School Transportation. Environment and Behavior, 1-20.