Nothing that happens in city traffic is isolated. Every driver and vehicle and every road, road marking, traffic control device, every sign, and every object in, near, or visible from the street, has an effect on the flow of traffic and its efficiency and safety.
Many of those with the power and responsibility to create and alter the traffic environment do not fully realize that. An observant experienced professional driver becomes aware of this inter-relatedness, using his perception to enhance the efficiency of his navigation. He is also aware of the many ways it could be improved.
Government agencies and legislative bodies attempt to improve the traffic environment, but often fail or worsen it because they do not look at the entire picture.
A great deal of public money is wasted in installing useless barriers and costly devices, while relatively cheap and more effective changes are left undone. Ideally, a driver should be able to go from one point to another with a minimum of stopping or slowing, thus allowing traffic to flow at a steady rate. To do this the driver must be as informed as possible about his location and the path he must follow to his destination. This information should be available with a minimum of distraction from watching the road and other traffic around him. Day or night the identity of streets should be visible without straining the eyes to read the sign. No signs should be obscured by anything else. Addresses of businesses and residences should be visible in a standard location. Driveways should be clearly marked by contrasting colors
Throughout the Greater Phoenix area, many stop signs are obscured by overhanging trees. Street name signs are unreadable from a distance, especially the small green ones. At night they are hard to read at all without stopping and using a flashlight. At many intersections from side to major streets, the view of oncoming traffic is obscured by walls, posts, or trees.
Instead of dealing with these potentially hazardous problems, huge sums are spent on such ill-advised devices as concrete medians and traffic signals with red left-turn arrows. The extended mediams make it difficult to turn into business or other driveways, requiring multiple left or u-turns to approach from the only accessible direction. Red arrows on left turns often force drivers to wait through two signal cycles before turning, even when there is no other traffic. Many will avoid them by driving further down the street and making a u-turn, which may be more hazardous than a turn at the light.
Doubtless the intention of such devices was safety, but the full effects were not carefully considered. Increasing the frustration level of thousands of drivers daily does not enhance safety. Forcing more left and U turns to reach the same destination is not safer.
In traffic, as in the universe in general, everything affects everything else. Those who would improve it need to consider that