“This weekend’s (9/28-9/29) plan:

There will be a track shutdown between the Orinda and Walnut Creek stations on both Saturday, 9/28 and Sunday, 9/29.  Free buses will replace trains between the Orinda and Walnut Creek stations.  Riders should expect delays of 40 minutes or more.  Also, the two left eastbound lanes of Highway 24 at Oak Hill Road are expected to be closed throughout the weekend to allow space for construction equipment.  Caltrans and BART will monitor backups in real time and will work together to reduce the number of lanes closed from two to one if driving delays approach 30 minutes.” – SOURCE AND MORE INFORMATION