While driving at 25 mph on a clear road in a city, you should be able to see about a block ahead. When traffic is heavy, you need extra time to react. This means drive more slowly. By reducing your speed, you may gain time. On city streets you may pass through intersections very often.
Many new drivers fail to see intersections.
When approaching or nearing intersection, reduce speed. Glance left and then right. Keep your foot on the brake. When you are at crosswalks, your car should be at its lowest speed. Decide whether to stop or go across.