Large cities have an amazing amount of foot and vehicle traffic. Some roadways will see more traffic in a month than a suburban or rural area may see in a decade. It is not surprising that transportation is highly controlled in urban areas. Planning is a good way to ensure traffic flow is contained to keep roadways passable and people moving within the city limits. Keeping maintenance in check with limited access and public transportation options also helps people move through the area without damaging roadways.
There are always a number of roadways that have restricted access for large or heavy trucks. These are generally smaller roads used for local traffic by cars and smaller vehicles. The reason heavier vehicles are kept out is to save wear and tear on the road or bridges. Not all roadways are built the same, and only flexible paving is in areas where heavy traffic abounds. This is because the weight is distributed downward on these special roads. It saves the pavement on the top from being crushed or broken by the heavy weights. Good urban planning provides access to all sections of the city with roads that will support their weight of their passage.
Rain and snow are two of the weather hazards of roadways throughout the world. Water cannot be allowed to pool, so it must be drained off the roads as it falls. Porous paving is generally the option for controlling water on urban streets. It allows water to pass through the pavement and into the ground below. Walkways in parks and beside roads are generally made with permeable paving materials. There are gaps between sections where the water is absorbed into the ground.
Keeping roads in good repair is financially draining on urban budgets. Governments can no longer afford large budgets for poorly built roads. Purchasing dried aggregates, even in bulk can become a costly exercise. Restricting access for heavy trucks is one of the best ways to limit the maintenance needed in large areas. Keeping personal vehicles off the roads with public mass transportation is another way.