Santa Clara Valley Transportation Authority light rail and bus service is shut down Monday as more than 1,500 front line employees have gone on strike.

Mediation failed to end the VTA and ATU Local 265 strike, leaving 100,000 riders affected as the union fights for better contract terms, despite a VTA lawsuit over the no-strike clause.

VTA’s final contract offer to workers last week included a wage increase of 9% over three years, keeping the employees as the second-highest paid in the Bay Area and the fifth-highest paid in the country. The union is seeking a 6% raise per year over three years and wants to add a clause guaranteeing arbitration for contract disputes.