Biking is big.

Chicago averages about 125,000 daily bike trips, and a new study has broken the trips into categories.

The majority of trips — 91,000 — are “utilitarian” trips, like going to the store or the library.

Using a bike to commute to work accounts for about 26,000 (a statistic that tripled between 2000 and 2012). School trips are 7,000.

The numbers used are based on individual rides, and not round trips.

The estimates, which do not include recreational biking, are year-round averages, and will balloon in warmer months and shrink in the colder ones, according to the Active Transportation Alliance, which commissioned the report.

The Active Transportation Alliance is a non-profit advocacy group that promotes bicycling, walking and public transit.

“The point is cycling is growing rapidly and the extent of cycling rivals the number of cars on our busiest streets,” said Ron Burke, executive director of the Active Transportation Alliance. “That’s a lot of people cyling. It drives home the point” that both cyclists and car drivers need to be “respectful” of each other as the number of cyclists grow on our streets.

“Our numbers are growing and it’s all the more important that everyone be respectful of each other,’’ he said.

Bike trips counted that weren’t before counted include biking to a store, a restaurant, a bar, a friends house, a library, Burke said, adding, “People haul stuff all the time on their bikes.”

The report contrasts the image of thousands of pedaling cyclists to the car traffic along two of Chicago’s best known streets. Western Avenue carries approximately 40,000 cars per day on its 23 miles. Lake Shore Drive carries 161,000 cars per day.

The study also finds:

◆ biking to work is most common among the lowest income groups.

◆ biking to work only accounts for approximately 21 percent of bike trips; most trips are “utilitarian.”

◆ Chicago bike counts found that winter biking has become increasingly common, with the winter biking counts equal to nearly 40 percent of summer counts.

◆ Chicago bike counts found that women accounted for 25 percent of observed cyclists in the winter and 31 percent in the summer.

◆ bike statistics are normally reserved for commuting to work, based on surveys conducted by the U.S. Census Bureau. The new analysis uses a regional household survey and other survey data to estimate “utilitarian” and school bike trips.