In the run-up to Bike to Work Day Friday, hundreds of companies and organizations are competing to be the office with the most commuter trips on two wheels.

More than 600 companies, government agencies and nonprofits are participating in Transportation Alternatives' Bike to Work Challenge throughout the week. Participating offices are broken down by number of employees. So far, 596 trips have been logged.

The leader for the most trips so far is Etsy, the DUMBO-based online shop, which has 92 participating members who have clocked 232 miles.

Employees of Transportation Alternatives, meanwhile, have biked about 144 miles. The nonprofit transportation group has a nearly 44% bicycle commute rate in its office.

Transportation Alternatives will announce the winners of the challenge Friday evening at the group's second Bike Home From Work party beneath the Manhattan Bridge archway at the Pearl Street Triangle and Anchorage Place between 6:30 p.m. and 9:30 p.m. The party this year includes a bike bell symphony, bicycle builders, and pop-up shops from local businesses.