Bike counts in Chicago

There are two types of counting cycling in Chicago. The first is to conduct automated counts, usually over 24 hours. The second is to conduct manual counts, usually at an intersection to also count turning movements of all vehicles.


How it works

A contractor is hired to conduct 24-hour counts at locations which CDOT determines. The locations may be different from year to year. Some locations may be counted twice in the same year. The counts are most often taken on weekdays. The count location may be repeated because of inclement weather during the first count.

Location selection

The locations chosen are usually related to where CDOT is planning to design and build a bikeway. The exact position in the road segment may be related to the location of an extant automobile count - when automobile counts are matched with bicycle counts, a mode share can be roughly determined. However, the comparison will only be between an aggregation those in automobiles (including taxis, semi-trucks, and transit buses) and those on bicycles. Additionally, the automobile counts are conducted sporadically and not annually.

The city has counted automobile traffic at hundreds of locations.

Years available

The last year available, that I know of, is 2009.

Equipment used

Pneumatic tube counting from Eco-Counter. The setup of this seems to have a high failure rate. There are more reliable devices available.

Two devices are set up at each count location, one device in each direction. The tubes are placed 12 inches apart so that the device's computer can detect a vehicle's speed and wheelbase. Any vehicle that travels faster than a certain amount, or has a wheelbase longer than a certain amount, is excluded from the count.

Data is extracted from the device using an HP iPaq running Windows CE over infrared.


  • Locations are not always repeated year after year, or more than once in the same year
  • Equipment setup fails, either in a single direction, or in both directions.

Manual counts

  • A handheld device is used to record the turning movements of all vehicles at an intersection. This is usually done twice in a single day, once from 7-9, and once from 16-18.
  • Or, volunteers use pens and papers to record them. See this interview with a volunteer counter, Alessandro Panella.

See also


/home/stevevance/ · Last modified: 2012/04/29 07:27 by stevevance
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