Car door vs. bicycle. My favorite T-shirt — a blue ringer — depicts that classic urban undercard: the pedaling, two-wheeled protagonist against villainous cold swinging steel.

I laugh at the shirt, a gift from friends, but I oughtn't. The match-up is usually won by the antagonist. In such a showdown, the hero tends to either go flying over a suddenly flung-open door and into traffic, or end up in a messy, tangled heap.

The one time I was doored (the writer knocks on wood), I got "lucky." A few years ago while cruising down Main Street Manayunk late one summer evening, headlight a-blinking and reflective tape a-reflecting, I found myself face to face with a car door.

I had just enough time to swerve, merely clipping my pedal on the edge of the door. I avoided a head-on collision, but not a scary roll-into-a-skin-shredding-skid onto the thankfully traffic-free pavement in front of Le Bus. As I sat catching my breath on the sidewalk in a chair one of Le Bus' outdoor patrons had offered me (and before I realized I was sitting, bloodied, with a bunch of folks out for a nice dinner), I contemplated reaming out the driver. But when I saw him — a sheepish, apologetic Latino man with his pregnant wife — I couldn't muster more than "Please look next time. I had a headlight." (I had also realized in that instant that nobody is even slightly intimidated by a screaming man in padded-crotch bike shorts.)

But that's the thing. That guy had no actual malice. There are people out there who do. Read artist/courier Stewart Dean Ebersole's Slant at right or Sam Tremble's preview of the Ride of Silence.

This is a problem for me. I'm trying to get my girlfriend on a bike. It's not that she doesn't know how to ride; but she hasn't since she was 12 and she's intimidated to ride in the city.

But she's trying. After weeks of me moaning — like an 8-year-old — about how I really want to ride my bike more, she's acquiesced. This weekend her parents hauled her old Huffy three-speed up from Maryland. And she swears that she's gonna give it a go, at least once she finds a sufficiently fashionable helmet.

Which is fitting since May is Bike Month, this week is Bike to Work Week and tomorrow (Friday) is Bike to Work Day.

A lot of ink has been spilled in these pages over the years about why biking is so important in a city like this. The reasons range from environmentalism to health to social justice. I won't go deeper here other than to establish that my pro-bike stance is not (just) some whimsical flight of fancy.

It's got to be tough at times like these for organizations like the Bicycle Coalition of Greater Philadelphia, whose mission involves making the city safer for cyclists and would-be cyclists. Part of that process is making drivers more aware of cyclists. Part of that is pointing out to drivers the dangerous and frightening things they do to cyclists. And that, I would imagine, makes would-be cyclists scared. It's not a small hurdle.

Earlier this week, the Bicycle Coalition held its fourth annual commuter race, wherein a cyclist, driver and a commuter on public transit raced from 45th and Spruce to City Hall. The cyclist came in first.

But it's not just about speed. Hopping on a bike can be a wonderful, head-clearing way to start or end a day. As the Bicycle Coalition's Alex Doty told the Inquirer, "When I bicycle commute, it changes a part of the day that is usually one of tedium and turns it into something that is joyful. ... I miss it when I don't do it. I don't think many other people miss their commutes."

Yes, there is danger associated with cycling — you could go flying headlong into a car door. But there's danger in driving. And when you're stuck on the inside of that car door in gridlock on Walnut Street or I-95, there's not a whole lot of joy.