Two-way traffic is the cause of many fatalities and other accidents on the road. Many roads could be made one-way when there is more than one possible route between two destinations. This would in effect make the routes dual carriageways and traffic would flow more easily, even if the national speed limit was kept to 60. Goods vehicles could be overtaken more safely, and there are many other advantages worth considering.
If councils were able to experiment with this idea they could easily test whether or not it would work, but I believe such experiments at the moment would have to be approved by Westminster.
There would be costs, such as changing road signs and the highway code, and re-educating drivers, but a vastly greater amount would be saved by the reduced costs of dealing with accidents, policing, and continually upgrading roads (or cancelling much-needed improvements because they are too expensive).
At first, it seems like a strange idea, but maybe it's worth considering…?