Local transit agencies are gearing up for the nasty "Frankenstorm" headed our way.

Neither Metro nor Virginia Railway Express has changed its service plans for the weekend or next week, but they warn they could need to reduce or even cancel some service. They urge riders to sign up for electronic alerts to stay informed about any service changes.

• Metro urges riders to sign up for its MetroAlerts, check online at wmata.com/sandy and viaTwitter @wmata. They urge riders to be careful on platforms and stay away from platform edges and curbs amid potentially high winds. To prepare, the agency is placing sand bags around the flood-prone areas and clearing drainage areas. It also is staffing up so more workers will be on-call if needed.

• Virginia Railway Express urges riders to enroll in Train Talk. If online access is limited due to power outages, riders can get updated service announcements at 1.800.RIDE.VRE(1.800.743.3873). Even so, the commuter train service urges riders to bring an extra bottle of water and packaged snacks in case trains are delayed by downed trees and the like.

• MARC riders also can sign up for electronic service alerts or they can call the MTA Transit Information Center Monday through Friday from 6 a.m. to 11 p.m. at 410-539-5000 or TTY 410-539-3497 for updated service information.