 Contrast this with motorways, which rarely have a high risk of head-on collision in spite of the high speeds involved, because of the median separation treatments such as cable barriers, concrete step barriers, Jersey barriers, metal crash barriers, and wide medians.The greatest risk reduction in terms of head-on collision comes through the separation of oncoming traffic, also known as median separation or median treatment, which can reduce road collisions in the order of 70%.Indeed, both Ireland and Sweden have undertaken large programmes of safety fencing on 2+1 roads.