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"surface=bitmac" handling

Tuesday 7 January
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I recently travelled to an area where a number of paved cycle routes were showing as "unpaved" on cycle.travel

On digging into the streetmap data, it seems this was because they were tagged with the "bitmac" surface type, instead of the more common "asphalt".

Could this be added to the list surface types cycle.travel considers to be paved? From what I can tell, bitmac/bitumen is merely a specific type of asphalt/tarmac, and the difference is immaterial to a bicycle.

Comments

Tue 7 Jan, 21:04

Dan, I don't know the extent the owner of this site will take on the responsibility to make the change, but it has to be made in Open Street Maps. Maybe you can learn how to edit and do it yourself?

Wed 8 Jan, 07:52

I don't know the technical differences, but "chipseal" might be a suitable replacement, and is a documented value. If the terms have a similar meaning, that documentation may be sufficient justification for such a change.

It's also sometimes useful to look at change histories in OSM to see why and how a tag was chosen. Often it's a bulk change, and sometimes there are comments explaining reasoning.

Wed 8 Jan, 11:26

The tag seems to be widely used in the UK, and isn't incorrect. Changing it to asphalt just to make it work with cycle.travel would be "mapping for the router", which is frowned apon practice in OSM. It would be a better permanent solution for everyone if cycle.travel just understood the value.

Wed 8 Jan, 11:51

I’ve added it and it will take effect at the next routing update. Keeping up with the tags people invent for OSM is a bit of a game of whack-a-mole sometimes…

Wed 8 Jan, 12:21

Cheers! I'll be sure to bring a chemistry kit next time I'm out surveying so I can determine the exact variety of asphalt in use...

Thu 6 Feb, 13:51

Just noticed this update has been applied now. Thanks for that!

I did notice one problem though: ways which use this tag, while now recognised as "paved", are still rendered with a dotted line on the map, which seems a bit contradictory. You can see an example here: https://cycle.travel/map/journey/701243

Thu 6 Feb, 17:33

Ah, well spotted. I’ll add that to the map code (it’s a separate process to the routing).

Fri 7 Feb, 11:50

Thanks again!

On looking into this tag some more, it seems "bitmac" is used almost exclusively by one exremely prolific mapper in Norfolk, to the extent that it affected route planning in the whole region. Funny the things that can happen in a collaborative editing environment with no hard rules!

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