The deteriorating Cimarron Street bridge will close Nov. 1, with traffic rerouted to three major streets.

A new, $8.5 million bridge will rise in its place over the winter, with a partial opening of four lanes and no weight restrictions planned for May 15. The new bridge, which will mirror the look of the just-opened Bijou Street bridge, will be completed by Aug. 25, city officials say.

The Cimarron Street exit off Interstate 25 will remain open during construction, but traffic will only be able to go west. Portions of Conejos Street will be closed periodically during construction.

Extensive detour signs are expected to route motorists to Bijou Street, Colorado Avenue or South Nevada Avenue. Sierra Madre Street, which runs north to south through the western edge of downtown, is expected to be a secondary detour route, perhaps favored most by local motorists.

In an effort to minimize the effects of the closure on downtown and west-side businesses, the detour plan was developed in cooperation with the Convention and Visitors Bureau, Old Colorado City Merchants Organization, Downtown Partnership and the Greater Colorado Springs Chamber of Commerce.

The Cimarron Street bridge was scheduled to be replaced in 2010, but that date was moved up when a chunk of the bridge roadway fell onto railroad tracks below in August 2006.

Since then, large trucks and RVs have been banned from the road, and traffic has been confined to one narrow lane in each direction on the northern section of the bridge. The southern half of the bridge has been demolished.

The new bridge will have four through lanes, two auxiliary lanes and bike lanes and pedestrian sidewalks on both sides. It is designed to allow three through lanes in each direction should U.S. Highway 24 west be widened or the Cimarron Interstate 25 interchange be redesigned.

The engineering firm CH2M Hill has designed the new bridge, and Lawrence Construction Co. will build it. Pre-construction work, including relocating utilities, is scheduled to begin Monday.

The Pikes Peak Rural Transportation Authority will fund the project through a 1 percent sales and use tax approved by voters in 2004. So far, city officials said, $1.17 million has been spent on design, temporary signage, demolition of the south half of the bridge, acquiring right of way and program management.

CONTACT THE WRITER: 636-0197 or bill.mckeown@gazette.com