Proposal:Mark bus lines that form the backbone of a public transport in a city with backbone=yes/limited/no
| Proposal:Mark the importance of a bus line with backbone=yes/limited/no | |
|---|---|
| Proposal status: | Draft (under way) |
| Proposed by: | Supsup |
| Tagging: | backbone=yes,backbone=limited,backbone=no, |
| Applies to: | 
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| Definition: | A backbone public transport bus route designed to have much more capacity, reliability, and other quality features than a conventional bus system. |
| Statistics: |
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| Rendered as: | Similar like subway relations are rendered as backbone (often BRTs) are as important to a city and people moving around it as subays are. |
| Draft started: | 2024-10-15 |
| RFC start: | 2024-10-15 |
Proposal
The new tag backbone=* would indicate that a route=bus functions as a backbone route in a city's public transport network. Often, these would be Bus rapid transit (BRT). Bus rapid transit is a public transport bus route designed to have much more capacity, reliability, and other quality features than a conventional bus system. Often it includes separate infrastructure, paying on the platform and to the busdriver, especially large buses etc. Values of the key would be yes/limited/no to allow granularity. A rule of thumb to consider a bus=route to be marked as backbone=yes is whether it functions similarly as a subway would.
Rationale
In some cities in the world, special infrastructure has been built for buses to make them a high quality service central to the city's public transport network. Often these are called Bus rapid transit (BRT) systems. However, just the fact that something is called BRT does not necessarily mean much; it can be just a part of branding. Some systems might not meet all the requirements for a BRT and still function as a backbone. As of now, OSM has not mechanism how to put some hiearchy to the importance of a bus route. However, a backbone bus route or good quality BRT can be as important a subway to the city. Renderers have no way to disaply such bus routes (that are quite visible on the ground due to dedicated infrastructure and usually branded and frequent buses) and routers cannot prefer them in case a user deems them more convenient (for examle to lower risk of a delay).
Consider this rendering of Prague by mapy.cz (the subway scheme is enclosed):
You can clearly see the subway lines highlighted, helping to navigate the city.
Now consider this rendering of Bogotá, (with BRT scheme enclosed) which has a well known backbone BRT system:
This proposal would allow for Bogotá's BRT to be rendered like Prague's subways. Of course, one should not tag for the renderer and mapy.cz is here just an example renderer, any renderer could do this and also other uses of the tag are possible.
There is related highway=busway, but it has its problems and is applied unevenly and as it marks physical infrastructure (which can be patchy with backbone bus lines not necessarilybeing on dedicated infrastructure all the time).
Tagging
There is a BRT standard run by Institute for Transportation & Development Policy that ranks some bus systems. Not all backbone systems are ranked by the institute and the rankings can also be old. Its scores are to be considered but how the system actually functions in the present is the deciding factor. Whether something is named a BRT is also not a deciding factor.
Mapper needs to consider whether a bus route has the following features:
- Faster than personal cars travelling alongside during rush hour
- Frequent service (context dependent, but definitely in minutes)
- Dedicated infrastructure (bus only ways)
- No payment ticket to the driver (off-board payment or selfpayment in multiple machines of the bus)
- Preference at intersections (no car traffic can block buses by turning left in countries driving on the right and vice versa, preferential green signalling)
| backbone=yes | If all the criteria are met (consider when BRT standrd gold or silver) |
| backbone=limited | If at least the first two criteria are met (consider when BRT standard bronze or BRT certified) |
| backbone=no | If either of the two first criteria are not met (this is the default value). |
Examples
. Refer to the wikipedia page for many examples of such systems: https://en.wikipedia.org/wiki/Bus_rapid_transit
Rendering
Of similar importance to how subway are rendered.
Features/Pages affected
Changes to the proposal
- October 17 13:30: A substantial rewrite based on early feedback
External discussions
Comments
Please comment on the discussion page.