Driving is sold on IMPATIENCE to teens busting out, much like tobacco was sold to improve their health. Advertising lies. More people die from both than anything else. Bicycling detoxifies road ragers.

Speed in cycling should be a reserve. Bike fit, carbon components, and skinny/slick tires do usher you along quicker when you need to outrun that rottie. But, in the city (with leash laws), I use my reliable "tank" hybrid outfitted with bomb proof wheels and kevlar tires. You need a bike that sits upright with straight bars to be seen, see, and stay in control. Mountain bikes are great for that, and build stamina for those long centuries in the country. Imperative to avoid flats in the city and on commutes, although at least one shop fixes while you wait.

You don't need a fugly to avoid theft, just a 6' cable with a sturdy lock in the messenger bag; goes around frame and most posts, and through wheels. Never leave my road bike unattended… too much invested.