Originally Posted by Ken Cox

The OP said "track bike" but he might have meant fixed gear.

Track bikes typically have a more aerodynamic riding position that puts significantly more weight on the handlebars and front wheel.

In comparison, a street fixed gear bike could still have a track frame, with a track frame's handling (and which I like), but with a riding position that suits the rider's preferences.

I commute and do all my transportation on a fixed gear bike.

My main bike has track geometry, but I have put a setback seatpost on it and flipped the six degree stem up, which gives me a more balanced position on the bike and makes the bike much more agile and user friendly.

The typical street fixed gear bike has a gear ratio somewhere between 72 gear inches and 78 gear inches, which allows a physically fit rider to cruise at about 20 mph.

I have geared WAY down to 61 gear inches, which allows me to comfortably cruise at 15 mph, and, because of my low gearing I have developed a very fluid spin that allows me to cruise at 20 mph with a little effort.

The 61 gear inches, though, also gives me great acceleration at intersections, as well as allowing me to ride safely without a brake (it took me four years of concentrated practice to get to the no-brake skill level, so please ride with a front brake).

Having no front brake makes frosty, icy mornings safer, since I don't have any possibility of subconsciously hitting the front brake and going down.

For the OP, I recommend a cheap but good dual pivot front brake with the brake lever in a handy position for use.

A single-speed free-wheeling bike means the rider will never learn to brake with his pedals, and so he will remain forever dependent on his brakes, and thus he will remain liable to a front brake fall on frosty or icy pavement.

I also have a fixed gear mountain bike set up with mega-fat studded tires for snow and ice, and I get around town on this bike when nothing else can move on the roads except the sand/snow-plow trucks.

This bike has cantilever brakes fore and aft, and, although I never use the brakes, I can foresee needing them in some of the conditions in which I ride.

I commute 15 miles round trip, and each leg takes about 30 minutes (stoplights included).