Hi Sergei, interesting question... Some time ago, I was also thinking of it. One could expect that "traditional roundabout countries" (such as the Netherlands, UK, Nordic countries) have higher level of safety. But you cannot assign this fact only to the number of roundabouts - it is rather a consequence of several factors, related not only to safe infrastructure, but also safety culture, behaviour, etc. - while all these elements are likely to be interrelated :-)

But if you plan such analysis, I can give you estimate of number of Czech roundabouts - approx. 1200. We had to count them on our own - there is no such database (at least in CZ).

Dear Jiří,

Thank you for your answer. Yes indeed, the state of road safety depends not only on the number of roundabouts .

I would be grateful if you would provide me with data on the number of roundabouts in your country in a few years, as well as the number of deaths in road accidents, the number of inhabitants of the country, the length of roads in those years and the area of the territory.

Thanks in advance.

It is not a problem to give you data on accidents, casualties, demography... But as mentioned, there is not any database on roundabouts. The number (1200) which I know, comes from counting which we did maybe five years ago. If I would like to know the numbers in different years, I have no clue how I could do it for you :-)

Dear

Existence of roundabout in the roadway system can control the speed and may increases density of vehicles in the roadway section. it may also cause traffic congestion an increases the number of conflict points between vehicles which causes accidents but with minor injury and property damage, casualties will be minimum due to low speed.

Dear Sergei,

Take a look at this article it might be helpful for you , it considers the presence of the roundabout as one of the independent variables that have used for modeling driver injury severity.

Hi, better late than never. I agree that number of roundabouts alone is not going to be a useful measure. Let's assume that roundabouts have a crash reduction factor of ~70% compared with sign-controlled intersections (a common finding in evaluatiions),. You could loosely argue that a jurisdiction with only roundabouts should have ~70% less intersection crahses, than a jurisdiction with only sign-conntrolled intersections. A crude measure of effect of more/less roundabouts on jurisdictions's road safety could be made using some sort of proportional sliding scale.

A zonal statistical crash prediction model could be developed looking at intersection crash risk in a jurisdiction based on % intersection traffic flow passing through different intersection types, including roundabouts. Speed limits would most likely have to be accounted for as well. And maybe land use proportions (urban/township/rural).

Such model could be useful in traffic management policy and planning.

Dear Sergei Azemsha ,

I considered, analyzed, and discussed this issue in a paper that is currently under the review process.

I analyzed a network of 1150 km of two-lane rural roads, in which more than 5000 accidents had occurred.

For each homogeneous section of two-lane rural roads, we evaluated the impact on road safety (in terms of yearly road accidents) of any intersections (both roundabouts and traffic lights or right of way intersections) included in the road section itself.

If the topic is still of your interest, feel free to contact me, I will be happy to discuss it once the article is published.