Yes, hapaXL, there is a traffic engineer.
Traffic engineering is a subject I studied in engineering school, and though I didn’t go into it, I have worked with a number of professional traffic engineers.
Cities definately work hard to improve traffic flow, particularly where traffic flow affects air quality. New roads and intersections are designed only after careful traffic projection and modelling of traffic flow. The difference between a modern road design and an older road design can be significant.
One difficulty in optimizing traffic flow is cost, particularly in cities that have an existing road system. For each intersection, the municipality has to decide what traffic control devices to use. In a lower traffic area, it may simply not be cost-efficient to install traffic signals with sensors that provide a protected left-turn only when cars are waiting.
Moreover, traffic engineering is usually primarily concerned with traffic flow at peak periods, rather than at times of minimal traffic flow like 3 am.
Sometimes, you’ll hit red lights every block because the lights are poorly timed. On the other hand, sometimes you’ll hit a lot of lights in one direction because the traffic lights are optimized for traffic flow in the other direction. If there is a lot of peak-direction traffic one way at certain times (e.g. heading to downtown in the morning and away from downtown in the evening), traffic engineers will often set up a traffic light progression that will allow the heavier traffic to flow smoothly while burdening the lighter traffic in the other direction.
Traffic engineering can make a large difference, though because of limited resources it cannot make everything perfect for everyone.