Earlier this week, DOT released its 2012 bike counts [PDF], including a new dataset — counts from the winter months. The agency has been tallying cyclists in December, January, and February for five years, and this year released the winter counts, in addition to April-through-October counts, for the first time. The data show that warm weather counts at the DOT’s screenline (the four East River bridges below 60th Street, the Hudson River Greenway at 50th Street, and the Staten Island Ferry) plateaued in 2012, while winter counts continued a steady upward trajectory.

Overall, the screenline count from April 2012 to February 2013 rose 4 percent over the year before. These gains are smaller than annual increases since 2008, but still bring the all-year bike count to 58 percent above 2008 levels. Compared to 2011, the numbers show a small drop in bicycling during the warmer months of April through October — about half a percent — but a 23 percent gain during December, January, and February of this winter.

DOT conducted its first screenline bike count in 1980. In 1985, the agency began collecting data annually. Since 2008, DOT has set up 10 weekday counts each year between April and October, running from 7 a.m. to 7 p.m. By overhauling its method, the agency could collect more reliable data. However, the screenline count remains a geographically-limited tool and doesn’t measure the full citywide cycling trend.

As part of its 2008 methodology change, the agency began collecting wintertime data, offering a fuller view of year-round patterns. These cold-weather numbers show that the difference between warm weather and cold weather cycling volumes is shrinking.

From 2008 to 2011, the winter bike count was between 40 to 47 percent of the size of the warm weather bike count. In 2012, that number jumped, with the winter count equating to 57 percent of the April-through-October count. There is still room for improvement. In Copenhagen, the winter retention rate is 80 percent.

“People aren’t riding in the dead of winter just for fun — they’re commuting and finding bicycling is a convenient option all year long,” said Transportation Alternatives in a statement.

While the winter ridership numbers are a positive sign, warm weather ridership can’t stay flat if the city is going to achieve its goal of tripling bike ridership in 2017 compared with 2007 levels. So far, the warm weather ridership has roughly doubled since 2012, according to the DOT index. An interesting pattern emerging from DOT’s data is that bike counts tend to increase in proportion to the expansion of the bike network the previous year. Relatively few bike lanes were built in 2011 — a peak bikelash year — which could explain the slowdown in cycling volumes in 2012.

More bike lanes should keep attracting more New Yorkers to take up cycling, though many of them might not get captured by the screenline count, especially if the city adds bike infrastructure farther out from the core. Better traffic enforcement from the NYPD and automated traffic enforcement cameras would also improve the culture of the city’s streets, making travel safer and friendlier for new bicyclists.

And another big boost to bicycling is looming on the horizon, with bike-share scheduled to launch this spring. In addition to putting more riders on the street, the bikes will have internal GPS, generating even more data on how New Yorkers get around by bike.