Everybody loves those night shots of a street with straight lights -- this is the effect created by headlights of cars.
This trick has been used for many years, since the invention of long exposure shots. It’s a perfect way to learn how your camera responds at night. You need a camera with bulb mode, loaded with 100 ISO film (any kind of film may work, I had experimented with this one only) maybe a tripod if you want to get really smooth shots and not move the camera during the exposure.
For best results, select a location with some kind of light source. For cars, it is best to get on a point higher than the street level — on a balcony, over a block, or on a bridge. This way, the cars will move straight. Take some time to find a perfect spot and unless you get a lucky shot. Experiment with exposures.
Try shooting at any aperture you want, the shutter speed is most important. Time must be, at minimum, 1 minute. Time your exposure with a chronometer or a stop watch. Doubling the time from 1 minute to 2 minutes is basically the same effect as opening the aperture one stop (from f5.6 to f4). But basically you’ll have to guess a lot.