The city’s bike lanes are often blocked by cars and trucks, according to a study released yesterday by two Hunter College professors.

The city has built 200 miles of bike lanes in the past three years, but the study found that cyclists will encounter a vehicle blocking a lane during a stretch of five to six city blocks more than 60 percent of the time.

The researchers surveyed 492 randomly selected Manhattan blocks that have bike lanes between Sept. 22 and Oct. 23.