The roads can be classified in many ways. The classification based on speed and accessibility the most generic one. Note that as the accessibility of road increases, the speed reduces. Accordingly, the roads can classify as follows in the order of increased accessibility and reduced speeds.
1) Freeways: Freeways are access controlled divided highways. Most freeways are four lanes, two lanes each direction, but many freeways widen to incorporate more lanes as they enter urban areas. Access is controlled through the use of interchanges, and the type of interchange depends upon the kind of intersecting road way (rural roads, another freeway etc.)
2) Expressways: They are superior type of highways and are designed for high speeds(120 km/hr is common), high traffic volume and safety. They are generally provided with grade separations at intersections. Parking, loading and unloading of goods and pedestrian traffic is not allowed on expressways.
3) Highways: They represent the superior type of roads in the country. Highways are of two types – rural highways and urban highways. Rural highways are those passing through rural areas (villages) and urban highways are those passing through large cities and towns, i.e. urban areas.
4) Arterials: It is a general term denoting a street primarily meant for through traffic usually on a continuous route. They are generally divided highways with fully or partially controlled access. Parking, loading and unloading activities are usually restricted and regulated. Pedestrians are allowed to cross only at intersections/designated pedestrian crossings.
5) Local streets: A local street is the one which is primarily intended for access to residence, business or abutting property. It does not normally carry large volume of traffic and also it allows unrestricted parking and pedestrian movements.
6) Collectors streets: These are streets intended for collecting and distributing traffic to and from local streets and also for providing access to arterial streets. Normally full access is provided on these streets. There are few parking restrictions except during peak hours.
Roads can be classified based on some other criteria. They are given in detail below.
Based on usage
This classified is based on whether the roads can be used during different seasons of the year.
- All-weather roads: Those roads which are negotiable during all weathers, except at major river crossings where interruption of tra c is permissible up to a certain extent are called all weather roads.
- Fair-weather roads: Roads which are negotiable only during fair weather are called fair weather roads.
Based on carriage way
This classification is based on the type of the carriage way or the road pavement.
- Paved roads with hard surface : If they are provided with a hard pavement course such roads are called paved roads.(eg: stones, Water bound macadam (WBM),Bituminous macadam (BM), concrete roads) layer they is called unpaved roads. Thus earth and gravel roads come under this category.
Based on pavement surface
Based on the type of pavement surfacing provided, they are classified as surfaced and unsurfaced roads.
- Surfaced roads (BM, concrete): Roads which are provided with a bituminous or cement concreting surface are called surfaced roads.
- Unsurfaced roads (soil/gravel): Roads which are not provided with a bituminous or cement concreting surface are called unsurfaced roads.
Roads may also be classified based on the traffic volume in that road, load transported through that road, or location and function of that road.
- Traffic volume: Based on the traffic volume, they are classified as heavy, medium and light tra c roads. These terms are relative and so the limits under each class may be expressed as vehicles per day.
- Load transported: Based on the load carried by these roads, they can be classified as class I, class II, etc. or class A, class B etc. and the limits may be expressed as tones per day.
- Location and function: The classification based on location and function should be a more acceptable classification since they may be defined clearly.