There are three main kinds of roads.
There is the national network of motorways and trunk roads. These should be vehicles only. There has been some expansion of capacity by adding lanes and improving some junctions. More needs to be done as these are much used and crucial to our economy. Their capacity could be helped if Rail freight could be be boosted by more sidings , single waggon marshalling and other ways to make it a more practical and viable option.
There are the local strategic roads, usually A designated. These should primarily be for vehicles. They should have mainly roundabout not traffic light junctions as these are better for flows. Road schemes which seek to remove capacity by narrowing, putting in exclusive use lanes , more lights and partial barriers should be discouraged. Junctions often need improving by increasing capacity . Lights need automatic sensors to switch to green where vehicles are waiting when they are no vehicles using the green that is available.
There are local roads which will often be mixed use. Here there may need to be further schemes to allow safe use by a variety of users, or to restrict parking where that creates obstacles to use.
The big change that is needed is to understand we need more capacity, and to see that making it easier to get through junctions on large roads  is a way to improve safety and reduce driver error. If the government wants economic  growth it needs to increase capacity of the national routes and the strategic local networks , issuing new guidance on junctions and budgets to get rid of bottlenecks, inadequate junctions and capacity shortages.