Classification of Roads

As we explained in section 3, it is impractical to go through the design process for every road. In addition, it is desired that there is a basic degree of standardization across all the roads in a city. To this end, we need to build design templates which can be then used at the construction of any new road that is being built. Given the variety of roads, there is a need to classify them depending on use and widths.

The IRC^2,7 classifies the roads as under:

1.      Expressway: Function of expressways is to cater for movement of heavy volumes of motor traffic at high speeds. They are generally signal free by providing with grade separation at intersections. Parking, loading and unloading of goods and pedestrian traffic are not permitted on these roads.

2.      Arterial: A general term denoting a street primarily for through traffic, usually on a continuous route

3.      Sub-arterial: A general term denoting a street primarily for through traffic usually on a continuous route but offering somewhat lower level of traffic mobility than the arterial

4.      Collector street: A street for collecting and distributing traffic from and to local streets and also for providing access to arterial streets

5.      Local street: A street primarily for access to residence, business or other abutting property.

The above is a good primary classification. In addition, the following should be used for further granularity

1.      Width: Since the design and traffic capacity of a road depends on the width, this should be a necessary parameter while classifying the road.

2.      Zone of use: That is, is this primarily in a residential, commercial or office area. Since usage patterns, parking, pedestrian requirements vary significantly between the above, this is also a necessary parameter while classifying a road

3.      Special uses: For example, is this road supposed to support BRTS. Or does this support a cycle track. Again, since for these types, the design template will need to be specially done, they need to be included in the classification.

So, as an example, one type of road based on this classification could be

Collector street, commercial, 24m width.

This needs to be worked out so that almost all (at least 90%) of the roads in the city can be covered in this classification

A similar approach and template designs are covered in IRC⁷. However, these reference designs are not comprehensive, and are primarily done only to give the desired width requirements.

…………. to be completed