Santa Cruz Metro announced quarterly service alerts starting Sept. 14, according to a release from the agency.

The highlighted service changes include:

• Route 18 — UCSC via Main Gate — Mission. Weekdays: Additional service will be provided; trips will run every 15 minutes from 8:35 a.m. to 7:50 p.m. Weekends: “ST” trips will be added; when “ST” trips are operating, service will run every 15 minutes from 1:25-7:25 p.m., and every 30 minutes through 9:25 p.m.

• Route 19 — UCSC via West Gate — Laurel. Weekdays: Additional service will be provided. Trips will run every 15 minutes from 8:20 a.m. to 8:05 p.m. Weekends: “ST” trips will be added; when “ST” trips are operating, service will run every 30 minutes from 12:05 to 9:05 p.m.

• Route 35 — Highway 9/Scotts Valley: Weekdays: An early morning trip will be added departing in the 5 a.m. hour, starting from Big Basin Way and Highway 9 (Stop ID 1236) in Boulder Creek to Country Club, then departing from Country Club (Stop ID 1247) at 5:15 a.m. to Santa Cruz. Weekends: An early morning trip will be added departing in the 7 a.m. hour, starting from Big Basin Way and Highway 9 (Stop ID 1236) in Boulder Creek at 7:18 a.m. to Country Club, then departing from Country Club (Stop ID 1247) at 7:27 a.m. to Santa Cruz. Seasonal service to Big Basin Redwoods State Park is discontinued until Summer 2024.

• Highway 17 Express: Weekdays: An early morning trip has been added for early morning commuters and travelers on early Amtrak trains and buses, departing Santa Cruz Metro Center at 4:56 a.m. and arriving at San Jose Diridon Station at 5:48 a.m. A southbound bus also has been added, departing San Jose Diridon at 6:18 a.m.

• Routes: 10, 15, 18, 19, 20, 69A, 69W, 71: Departure and arrival times have been adjusted on both weekdays and weekends.

For information on Santa Cruz Metro, visit scmetro.org.