How do we classify expressways in India? The obvious way is to just tag all expressways with highway=motorway, but this comes with conflicts, because highway=motorway usually implies access restrictions (usually slower vehicles are not allowed). Further many “expressways” in India aren’t really expressways. They don’t have the signage as per the Vienna Convention. They don’t necessarily use proper interchanges, instead allowing traffic to merge with frontage roads, before merging with the main carriageway.
Examples of such roads include NH48 between Tumkur and Davanagere, where almost all at grade crossings have been eliminated, in favour of flyovers and underpasses. But there are still one or two u-turn points with open medians, and there are no interchanges, instead the other road meets the service lanes at grade, and traffic is expected to merge with the main travel lanes using the service lanes. Currently this route is classified as highway=trunk + motorroad=yes, but this is again inappropriate because there are no access restrictions for slow moving vehicles on this road.
Another edge case is when there is a long flyover between a pair of junctions, usually in urban areas, above a National Highway. An example would be the BETL between Bommasandra and Electronic City. These flyovers may or may not feature access restrictions for slower vehicles, but are usually tagged with highway=motorway. It might be appropriate to reclassify them as highway=trunk + expressway=yes, since they are meant as a bypass for the existing National Highway traffic, they are not really expressways unto themselves. BETL in particular has a low speed limit (60kmph) and doesn’t have a shoulder, so tagging it as a motorway doesn’t seem accurate.
Given this ambuigity, I feel we might need to revisit classification for “expressways”. I propose the following:
highway=motorway => Fully access controlled, uses the Vienna convention expressway signs. E.g. all National Expressways, Mumbai-Pune Expressway, etc
highway=trunk + motorroad=yes => Full access control, no entry for slower vehicles, but does not use Vienna convention signage. E.g. NH275 between Bengaluru and Mysuru
highway=trunk + expressway=yes => Full or partial access control, no ban on slower vehicles. E.g. NH648 between Devanahalli and Hosakote, BETL, etc.
Effectively we would use expressway=yes to indicate roads with better access control and higher level of service, while motorroad=yes would be used only for indicating if a road is behaving like a motorway. This has precedent in US and UK, where expressway=yes is used in a similar manner.
ika-chan
(Sharks with laser beams attached to their heads!)
2
The use of highway=motorway is close to being out of control in India in my opinion. I think that classification is meant for expressways with a motorway sign, but some obvious cases like the ORR of Hyderabad don’t have them from what I can see on Mapillary imagery.
At the same time the uncontrolled use of highway=motorway, and highway=trunk + motorroad=yes, risks creating problems for navigation by non-motorway means, such as walking and mopeds.
Note: motorroad=yes was corrected from expressway=yes.
Yes, NICE road is similar. It would end up being tagged with highway=trunk+motorroad=yes, since similar restrictions apply.
expressway=yes does not imply access restrictions for pedestrians/cyclists, where as motorroad=yes does, which is another reason to use the expressway key for some of the roads. Currently some of the roads tagged with motorroad=yes do not prevent pedestrians/mopeds from using them.
ika-chan
(Sharks with laser beams attached to their heads!)
4
Sorry, I have to correct that we should use motorroad=yes only for roads with motorway-like restrictions, and that said tag does not need to be limited to trunk roads. I find that expressway=yes may be a duplication of motorroad=yes in India’s case.
We should also remind mappers that granular access rules can also be tagged according to Key:access - OpenStreetMap Wiki. For example, roads to private property use highway=service + service=driveway + access=private.
expressway=yes would be useful for the golden quadrilateral, and some other national highways which have better grade separation and road design. Currently a portion of NH44 and NH48 are both tagged with motorroad=yes, but they could be tagged with expressway=yes since they are higher speed/higher quality roads, but not fully access controlled.
A lot of highways under construction were mapped as motorways by a single mapper. Arun Ganesh made a changeset comment two months ago, but did not get any reply. I started to change this mappings.
red : motorways
yellow :expressway=yes
blue :motorroad=yes
green :construction=motorway
I had a look on the mapping in UK and USA; there are inconsistencies (errors):
UK : motorroad=yes together with expressway=yes
USA: even highway=path with motorroad=yes
The two occurrences appear to be typos for motorcycle=yes, based on other ways that were introduced in the same changeset. Fixed.
Apart from that, motorroad=yes was historically a tag that some mappers in the U.S. used to indicate roads with expressway design characteristics, due to a misunderstanding about the meaning of this key. (We don’t have an equivalent access restriction in the U.S.) motorroad=yes was never as popular as highway=trunk for indicating expressways. In recent years, the community has discouraged both practices in favor of expressway=yes. This key has been around for a long time but languished in obscurity until a renderer came along that made use of it.
I’ve replaced motorroad=* with expressway=yes for NH44 between Bengaluru and Kanyakumari. The changes can be seen on Americana OpenStreetMap Americana . Also I removed some incorrect motorroad=yes instances with the help of Heinz’s overpass query.