A transit strike combined with 30 centimeters of snow left behind by a winter storm sent a wave of chaos through Canada's capital yesterday as many commuters scrambled to find ways to get to work, school and other appointments.

About 2,100 drivers, dispatchers and maintenance staff finished their overnight shifts and walked off the job early yesterday morning, crippling the morning commute.

City officials say they are bracing for a 20 percent increase in traffic as the strike forces many residents to get back in their cars. City contingency plan for a strike includes asking people to carpool and stagger work hours. Some downtown bus lanes are open to traffic and street parking hours have been extended.

The transit strike comes after talks broke off Monday afternoon when the transit union rejected the management's final offer. The city offered the union a 7 percent wage increase over three years, but the union was asking for a 10.5 percent pay raise over a three-year period.

A mediator from the federal government is meeting independently with both sides.

Ottawa's transport buses provide service to about 350,000 riders on an average day.