Already, the strike has transformed some habits.
This morning, software developer Gary Stewart, 39, got one of the last spots in a long line of bike racks outside the Comcast Center.
No, his regular means of transport - a regional rail train from Lansdowne - wasn't shut down, the way buses, subways and trolleys were.
The problem: The waiting became intolerable.
"Yesterday, I couldn't get on three different trains," he said, explaining they were filled farther up the line.
The third train, which usually has four cars, had only two, "which is absolutely ridiculous," he said.
So he pedaled nearly seven miles this morning.
"If it rains, I will probably work at home," he added.
Philly's usually a bike-friendly city, said Stephanie Singer, 28, a marketing strategist at BAJ Design, who almost always rides her bike about a mile and a half to work.
She observed, however, that because of the strike, not only was car traffic up, but courtesy was down, as harried drivers ran more yellow lights and blocked bike lanes.
Yesterday, heading home with five other bikers, they got stuck behind a car that hogged the bike lane for an entire block, she said.
Safety's a big worry for cyclists, she said.
"I'm a huge fan of helmets," she added, recalling how a cycling friend got killed by a bus a couple of years ago.
The visibility of helmets helps make driver more conscious of bikers, she said.
Nearby, at the intersection of 17th Street and JFK Boulevard, a cab swerved toward the curb, oblivious to an oncoming biker, who jammed on his brakes - then chose to go around on the sidewalk.
Several other bikers ignored one-way signs to cross the boulevard in the wrong direction.
A man on a moped stopped at the light - carrying big clear bags of what looked like laundry on the back - but a cyclist, after scooting between cars, continued right through the red light.
