45: Temporarely widening or narrowing of roads
In our country, only double crash barriers are used on both sides of the central reservation of motorways. Around the big cities, it would be good if these were replaced by single or double concrete elements during the next maintenance.
The problem is that commuters want to travel to the city in the morning and out of the city in the evening. This means that in the morning there is a traffic jam in the direction of the city and in the evening in the opposite direction. Also on Sunday evening, when people come back from the weekend, there is often a traffic jam towards the city while on Friday evening there is a traffic jam in the other direction.
Concrete elements allow for the use of a zipper that simply solves this problem. Roads are temporarily widened or narrowed if need be. This will prevent a lot of superfluous traffic congestion.
The dismantled crash barriers can be used in other places, for instance to protect motorcyclists. (Chapter 39)