The frenetic pace of many of the commuters walking across town on 34th Street during the morning rush is born out of a certain necessity: If they walk fast enough, they can outpace the bus.

For the second year in a row, the M34 crosstown bus in Manhattan has been identified as the slowest bus in the city, according to a study released yesterday by the Straphangers Campaign and Transportation Alternatives. The survey, called the “Pokey Awards,” has been conducted for the past four years.

The average speed of the M34 was clocked at 3.4 miles an hour, the same as last year. People who walk “briskly,” a designation that would include most rush hour commuters, average 3.5 miles an hour. Casual walkers, meanwhile, travel at about three miles an hour, according to the Wellness Letter, a newsletter published in partnership with the University of California’s School of Public Health. The Straphangers conducted the survey by riding the 23 bus routes found slowest last year, starting at noon, between July 15 and August 8. The study said 11 of the 23 slowest buses are in Manhattan.