In the United States, every state has the right to make the law that would stipulate the speed limits across its territory. In many cases, the local civic authorities such as municipalities or counties or other subdivisions can also set the speed limit. Speed limits don’t just vary across the country but they can vary every few miles depending on where you are driving, the type of road and the kind of habitation in the area.
The speed limit range bottoms out at 35 mph and peaks at 85 mph. Usually, the increment or decrement of speed limit is by 5 mph. This range is not a given nationwide as there are plenty of exceptions, both with the least and highest speed limit.
Considering the speed limits across the country, you would find the highest range of 75 mph to 85 mph along the west coast and national or interstate highways connecting the western states. The east coast or eastern states are more inclined towards a limit of 70 mph. There are exceptions such as Hawaii that doesn’t allow a speed limit higher than 60 mph. Washington DC has a max speed limit of 55 mph.
In Texas, it is the Department of Transportation which is a state authority that statutes and enforces speed limits. The law in Texas requires speed limits to be the maximum allowed in the state so everywhere you drive in the state should have the maximum permissible speed limit unless there are engineering concerns or traffic considerations. Safety is of paramount significance when setting the speed limits.
The state law stipulates and caps the maximum speed limit at 70 mph. The Texas Transportation Commission has the right to review this and can increase it to 80 mph and even 85 mph if there is evidential backing in the form of engineering of the roads, traffic and safety studies.
In Texas, speed limit for freeways in rural areas is 75 mph up to 85 mph, for freeways in urban areas is 55 mph to 75 mph, for divided rural areas is 75 mph and undivided rural areas is 30 mph to 75 mph. For residential areas, the speed limit is 15 mph to 55 mph.
The speed limit in Texas is influenced by the engineering of the road, including the materials used for construction, the route, expected traffic flow, intersections, road curvature, lane width, shoulder area, banking, noise pollution and expected development in the area.