Here's information provided by the City of Livermore:
Portola Avenue will be temporarily closed from Isabel Avenue/Campus Hill Drive to East Airway Boulevard to repair wildlife roadway crossings. The road will be closed on Tuesday, Sept. 25 and reopened prior to the morning commute of Friday, Oct. 5.
Traffic will be temporarily detoured to Isabel Avenue and East Airway Boulevard as shown in below map. Please follow directional signage and drive carefully.
For information on the Isabel Ave/I-580 Interchange improvements, visit the city's website.