DANVILLE -- A new freeway widening project will lead to night time lane closures for weeks on Interstate 680 between Sycamore Valley Road in Danville and Crow Canyon Road in San Ramon.

Various lanes will be closed from 8 p.m. to 5 a.m. Mondays through Thursdays, and from 8 p.m. Fridays through 8 a.m. Saturdays. Some freeway ramps also will be closed at night.

Caltrans said the closures are needed because construction has begun on a $34 million project adding merging lanes on I-680 between the two major roads in Danville and San Ramon.

The lanes will make it easier and safer for vehicles to merge as they enter or exit the freeway, officials said.

Caltrans and the Contra Costa Transportation Authority are jointly overseeing and funding the auxiliary lane project due to be finished by the end of 2013.

To ask questions or make comments about the project, call 925-262-1158 or send an email to I680auxlanes@gmail.com

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff