Observations on Indian Roads
(This is a x-post from my OSM Diary)
The OSM Urban Road classification guidelines for India dictate a number of high-level directions on mapping roads in Indian cities. When Devdatta and I tried to fix some classifications in Pune, we realised that the current guidelines don’t provide a solid base for decision making, in an “if X, then Y” way. So we decided to observe, annotate, experiment and retrospect on whether a classification makes sense.
We realised that to map a road, one must understand how a road is perceived, and its purpose in the larger scope of the neighbourhood, locality or city. This gives the road a purpose, and that purpose defines its classification. The purpose or intent of the road is not enough to classify it, so we tried to observe a few other factors that characterise roads in major Indian cities. Here’s what we found.
- Much like a river, a road begins somewhere and merges into another road. As roads connect with each other, the larger road essentially “collects” traffic from a smaller road. However, it is not necessary that a smaller road feeds into a larger road. Often, it might feed into a road of the same size, but with elevated purpose.
- Some roads serve the same purpose but could vary wildly in their characteristics, including the width of a single lane.
- Many collector roads can be easily identified using tell-tale signs such as the presence of speed bumps, traffic signals and dividers.
The observations led us to try and categorise roads based on a few factors:
| Class | Rank | Usually feeds into | Definition | Lanes in One Direction | Traffic Signal | Divider | Flyovers | IMG | |
|---|---|---|---|---|---|---|---|---|---|
| Motorway | 1 | Trunk/Primary/Motorway | Access controlled roads, usually elevated on flyovers and specific entry, and exit points. | 2+ | n | y | y | 1 | |
| Trunk | 1 | Trunk/Motorway | Sections of the National Highways inside the city. Serve as arterial roads in the same essence as primary roads. | 2+ | y | y | y | 1 | |
| Primary | 1 | Primary + | Connects major localities and major thoroughfares to travel from one side of the city to another. Usually has multiple lanes and complex junctions. | 2+ | y | y | y | 1 | |
| Secondary | 2 | Secondary + | Connects two or more neighbourhoods or suburbs, and may serve as a collector for tertiary, residential, and Rank 5 roads. It may feed into other secondary roads. | 2+ | y | y | y | 1 | |
| Tertiary | 3 | Tertiary + | Serves as a main road within a neighbourhood/suburb. Serves as a collector for residential roads, and other Rank 5 roads. | 1-2 | n | n | n | 1 2 | |
| Residential | 4 | Residential+ | Narrow road with two way-traffic, generally has houses, residential buildings, offices and amenities, may contain footpaths and parked vehicles on the sides. It may have roundabouts and other junctions. May serve as a collector for Rank 5 roads. | 1-2 | n | n | n | 1 2 3 4 | |
| Service | 5 | Residential+ | An internal road used to access buildings, typically part of an internal network for housing societies, commercial complexes, warehouses and industrial areas. May have one-ways. Access is typically, but not always, limited. | 1 | n | y | n | 1 | |
| Living Street | 5 | Residential+ | A narrow road used by pedestrians and two-wheelers, barely allowing two-way traffic. Cars may or may not be allowed, but may not be able to pass due to foot traffic, parked vehicles, and the width of the road. | 1 | n | n | n | 1 |
While the observations may not be empirical, they were helpful in trying to classify roads, especially in Pune and served to enable decision-making during classification. The biggest challenge in India is that every road collection comes with an ‘at time but not always’ clause attached to it. You will find residential roads feeding into state highways, roads narrowing down midway, and other strange occurrences due to land ownership and acquisition issues or just because of poor planning.
We would love community input on these observations so that we can all have better-classified roads.