Carriageway
Definition
A 
Carriageway[1] is defined in Wikipedia as:
a width of road on which a vehicle is not restricted by any physical barriers or separation to move laterally. A carriageway generally consists of a number of traffic lanes together with any associated shoulder, but may be a sole lane in width (for example, a highway offramp).
This is closely related to the definition of carriageway in the Vienna Convention on Road Traffic [2]:
“Carriageway” means the part of a road normally used by vehicular traffic; a road may comprise several carriageways clearly separated from one another by, for example, a dividing strip or a difference of level;
The carriageway is defined here as a part of the road, which is in turn is defined as:
"Road” means the entire surface of any way or street open to public traffic;
Relation with other parts of a road
A road can consist of zero (in the case of a cycle track or footway as an independent road), one or multiple carriageways with physical separation.
A carriageway can contain facilities for non-motorized traffic (such as a cycle lane separated from the rest of the carriageway by longitudinal road markings[3]),
but facilities for non-motorized traffic can also be constructed as separate parts of the road such as a sidewalk[4] physically separated from the carriageway by a curb or verge or a cycle track[5]
The illustration below shows several configurations of roads with one or more carriageways
Related concepts in Openstreetmap
- bicycle=use_sidepath: used on ways
in OSM that represent a carriageway to express that this way may not be used by cyclist, but instead a compulsory parallel highway=cycleway should be used (that is mapped as a separate way in OSM) - foot=use_sidepath: used on ways in OSM that represent a carriageway to express that pedestrians should use a parallel mapped highway=footway (possibly with footway=sidewalk ) instead of the carriageway
- width=* : when used for streets : describes the width of the carriageway from kerb to kerb -excluding anything beyond the kerb/edge like sidewalks, cycle paths or street side parking, even if the way in OSM also represents the sidewalk (no separate way in OSM for the sidewalk, but only tags on the main way such as sidewalk=both . Cycle lanes that are separated only by longitudinal road markings (without physical barriers) are a part of the carriageway and are included in the value for width=*
References
- ↑ or "roadway" in North American English
- ↑ https://unece.org/DAM/trans/conventn/Conv_road_traffic_EN.pdf( Article 1 )
- ↑ “Cycle lane” means a part of a carriageway designated for cycles. A cycle lane is distinguished from the rest of the carriageway by longitudinal road markings; In Vienna Convention on Road Traffic, article 1:
- ↑ or "pavement"
- ↑ “Cycle track” means an independent road or part of a road designated for cycles, signposted as such. A cycle track is separated from other roads or other parts of the same road by structural means; (Vienna Convention on Road Traffic article 1)