How is a Road's Star Rating Assessed?

The system includes measures of how well traffic lanes are separated

...checks for roadside protection

...checks for junction layout and design

The Star Rating scoring system is based on a schedule of detailed road design elements that correspond to each of the four main crash types that kill and maim on Europe's roads. A road's Star Rating combines each of the three elements below.

1. Head-on Crashes: measures of how well traffic lanes are separated
2. Run-off Crashes: checks for roadside protection (for example, safety fencing protecting rigid poles, lampposts and trees)
3. Junction Crashes: checks for junction layout and frequency

Motorways generally have crash protection features in harmony with the high speeds allowed. The Star Rating results show that motorways generally score well with a typical 4-star rating even though their permitted speeds are the highest on the network. But results from Star Rating research in Britain, Germany, the Netherlands and Sweden have shown that there is a pressing need to find better median, run-off and junction protection at reasonable cost on single carriageway roads. These roads typically score 1 or 2-stars and safety standards can be variable even on main national or regional routes. Even busy single carriageway roads rarely have safe separation between opposing traffic streams and the margin for error for vehicles running off the road is typically thin.

The process of Star Rating is encouraging the development of innovative engineering for "forgiving roads". The development of single carriageway main roads with central safety fencing and regular provision for protected overtaking is being taken forward in Sweden, Ireland and elsewhere. Lattix posts, which crumple on being struck, are entering national road engineering standards. Safety fencing to prevent run-off accidents which is sufficiently environmentally appealing, even for use in national parks, is being installed. The aspiration of some engineers is to create design elements which together could lead to affordable 4- star single carriageways on important main roads.

Road inspection programmes are well developed in Sweden and Germany. Programmes are now rolling out across Europe with developments in Austria, Britain, Iceland, Ireland, Netherlands, Spain and Switzerland.