SAN DIEGO–Caltrans began activating meters on eastbound State Route 78 (SR-78) this week for the morning commute.

Affected locations are Civic Center Drive, Mar Vista Drive and Sycamore Avenue in the city of Vista.

A total of 22 on-ramps will be activated in groups of three through August to help reduce the duration and extent of congestion on the freeway. Ramp metering at the new locations will take place on eastbound SR-78 from 5:30 to 9:30 a.m. and on westbound SR-78 from 3 to 7 p.m.

Eastbound SR-78 5:30 to 9:30 a.m. ramp meter activation locations:

· Tuesday, June 28: Emerald Drive and Vista Village Drive in Vista.
· Wednesday, July 6: Jefferson Street and Plaza Drive in Oceanside.
· Tuesday July 12: Twin Oaks Valley Road, Barham Drive/Woodland Parkway and Nordahl Road in San Marcos.
· Tuesday, July 19: Rancho Santa Fe Road, Las Posas Road/Grand Avenue and San Marcos Boulevard in San Marcos.

Westbound SR-78 3-7 p.m. ramp meter activation locations:

· Tuesday, July 26: Mar Vista Drive, Civic Center Drive and Vista Village Drive in Vista.
· Tuesday, Aug. 2: W. Vista Way, Emerald Drive, northbound College Avenue in Oceanside.
· Tuesday Aug. 9: southbound College Boulevard, El Camino Real and Jefferson Street in Oceanside.
Warning signs will be placed at least a week in advance of activation to alert motorists about the change.