L.A. began its first work week of “Ramp Jam”–the three-month closure of the westbound Wilshire Boulevard onramp to the northbound San Diego (405) Freeway and the northbound 405’s offramp to westbound Wilshire.

The ramps were closed Friday night in the first phase of a yearlong effort to demolish and rebuild all eight ramps at the interchange. They are to be replaced with ramps designed to reduce traffic jams and dangerous lane-weaving. The work is part of a project to add a 10-mile carpool lane to the 405 through the Sepulveda Pass.

The ramp closures are proving to be a source of anxiety for thousands of commuters scrambling to find alternate routes to and from the westside, and residents of Westwood and Brentwood who expect that already congested routes–Sepulveda, Santa Monica and Sunset boulevards, for example–will experience even worse traffic jams.

The Veterans Affairs West Los Angeles campus has advised employees to allow twice as much time as usual for commuting, the Los Angeles Times reported. To reduce cut-through traffic and help ensure access for emergency vehicles, the campus plans to close its gates on Eisenhower and Gorham avenues.

UCLA has urged employees to telecommute, work alternative hours and carpool, bike or walk, according to The Times. And Blair House, a Westwood condo building on Wilshire, has agreed to subsidize monthly bus passes for its employees and caregivers, housekeepers and other workers employed by residents.