| Road type code | Physical characteristics | Location | Typical speed limit | Traffic characteristics | Safety characteristics | Weather and environmental characteristics |
| UM | 2x3 lane motorway or expressway with hard shoulder (divided carriageways, grade-separated junctions) | Urban ring road | 70-100 km/h | Busy all day, congestion on weekday rush hour peaks in both directions, mix of cars and heavy vehicles | Critical safety problems: frequent accidents and incidents (rear-end shunts, accidents due to lane changing, etc) | No weather problems. Local environmental pollution and noise problems |
| UR | 2+1 lane road (single carriageway, at-grade junctions with traffic signals) | Urban radial road | 50-70 km/h | Busy all day, congestion inbound in morning peak, outbound in evening, mostly cars, frequent bus services | Moderate safety problems: speeding when road is not congested, safety of pedestrians, conflicts due to stopping vehicles (buses, deliveries, roadside parking) | No weather problems. Local environmental pollution problems |
| IM | 2x2 lane motorway with hard shoulder (divided carriageways, grade-separated junctions) | Interurban – part of Trans-European road network in mountainous area, including tunnel and viaduct sections | 110-130 km/h | Moderate traffic, high degree of international long-distance traffic and heavy goods vehicles, high proportion of foreign drivers | Low accident rate but some potential for serious accidents involving heavy vehicles in tunnels or in bad weather | Winter weather and change of weather condition problems. Local environmental pollution and noise problems |
| IR | 1+1 lane main road with hard shoulder on some sections (single carriageway, mostly at-grade junctions including roundabouts) | Interurban – part of Trans-European road network | 80-100 km/h | Moderate traffic with mix of national and regional, including all vehicle types (cars, heavy vehicles, buses, cyclists and localised slow-moving farm traffic) | Moderate accident rate: problem of speeding and mix of slow and fast vehicles, cyclists, horses, tractors, etc. Some sharp bends or other geometry-related hazards | No severe weather problems. Local environmental pollution and noise problems |
| RR | 1+1 lane secondary road with no hard shoulder | Rural – regional road in mountainous area linking ski resorts | 60-90 km/h | Mostly low traffic, but severe congestion a few weekends a year with winter holiday traffic. Breakdowns or accidents likely to block road | Moderate accident rate, due to speeding, frequent sharp bends, ice and snow in winter | Severe winter weather problems, environmental pollution when congestion occurs |