Proposed features/gross weight

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gross_weight
Status: Proposed (under way)
Proposed by: martinq
Tagging: maxgcweight, maxgcweightrating, maxactualweight, maxweightrating=-
Applies to: --
Definition: To express limitations/restrictions of the acutal weight, weight rating of vehicles and combinations (trailers) and to express conditional restrictions based on weight properties
Rendered as: Not rendered on default map
Drafted on: 2013-06-16
RFC start: 2013-06-18
Vote start: --
Vote end: --


The issue

Background

Many countries of the world have implemented the Vienna Convention on road signs. This convention - and therefore the road signs - uses two types of weight:

  • Actual weight (defined as laden mass) = actual mass of the vehicle as loaded, with the crew and passengers on board [from Article 1(s) of the convention]
  • Permissible maximum weight (defined as permissible maximum mass) = maximum mass of the laden vehicle declared permissible by the competent authority of the State in which the vehicle is registered [from Article 1(r) of the convention]

Additionally, weight limits either apply to vehicles (truck and trailer are two distinct vehicles, this is consistent with the current access=* key) or for the combination of truck and any trailers (sum of weights).

Current situation

In OSM only two weight-related tags exist, both not absolutely precise whether "actual weight" or "permissible maximum weight" is meant:

  • maxweight=*: Not clearly stated in the text, but due to the road sign used as illustration, which is internationally expressing "No entry for vehicles exceeding X tonnes laden mass" (see section C, II., 1(e), C,7 in the convention) it is potentially intended as - and used for - laden mass.
  • Conditional_restrictions: Only the property weight is defined, but it does not clearly define it refers to actual weight or GVW.

This issue around 'weight' and its unclear meaning has been discussed before here in the wiki (Talk:Conditional_restrictions#Addition:_Gross_vehicle_weight_rating) as well as on mailing lists.

The consequence

For data users (for example HGV routing) the information maxweight=5.5 can either mean that a truck and trailer with 5t each (and 10t in sum) is allowed to pass if the mapper meant Vorschriftszeichen 9c.svg, or that an empty truck with trailer having less than 5.5t actual weight is still not allowed to pass if the mapper meant Vorschriftszeichen 7a Gewicht.svg, because it exceeds the GCW value in the vehicle documents. This results in limited use of maxweight due its inherent ambiguity.

Proposal

Tags

The proposal is to replace the ambiguous maxweight by following set of keys that refer to a specific weight type (column "Poland variant" documents an alternative schema developed in Poland and is not part of this proposal):

Tag Definition Poland variant
maxactualweight=<value> Vehicles with an actual weight exceeding the given value are not allowed to access the way or pass the node with this tag.

The actual weight is the weight of a vehicle with it current load, the crew and passengers on board (=the weight measured on a weighbridge). The actual weight can be influenced by the driver by unloading or loading the vehicle.
maxactualweight taginfo:

maxgvweight
gvweight means gross vehicle weight

maxgvweight:hgv taginfo:

maxweightrating=<value> Rating means the maximum permissible weight of a vehicle as defined in vehicle registration documents or vehicle documentation (also called gross vehicle weight rating = GVWR).

Vehicles with a rated weight exceeding the given value are not allowed to access the way or pass the node with this tag. The rating cannot be influenced by the driver, except by changing the registration (e.g. down-plating).
maxweightrating:hgv taginfo:

maxgvweightrating

maxgvweightrating:hgv taginfo:

maxgcweight=<value> Vehicles with an actual gross combined weight (GCW) exceeding the given value are not allowed to access the way or pass the node with this tag.

In OSM the GCW is the actual weight of the combination of towing vehicles plus any trailers including load, crew and passengers (weight on a weighbridge if towing vehicle and any trailers are measured together). It also applies to vehicles without trailers: In this case the actual GCW is identical to the the actual weight of the vehicle alone. Note: Originally the proposal suggested maxgcw as key. There were less than 10 uses for this key when the proposal was updated. The use of "gcweight" is preferrable, since it makes it self-evident that they key describes a kind of weight restriction.
maxgcweight taginfo:

same key, proposal was updated
maxgcweightrating=<value> Vehicles with a permissible gross combined weight (also known as gross combined weight rating = GCWR) exceeding the given value are not allowed to access the way or pass the node with this tag. The rating is defined in vehicle registration documents or vehicle documentation.

Note: Originally the proposal suggested maxgcwrating as key. There were less than 10 uses for this key when the proposal was updated. The use of gcweightrating is preferrable, since it makes it self-evident that they key describes a kind of weight restriction.
maxgcweightrating:hgv taginfo:

same key, proposal was updated

Limit for vehicle category

Similar to maxspeed or other max... keys: Weight limits that only apply to a specific vehicle category (see access=*), can be tagged by adding the vehicle category: maxweightrating:hgv expresses a maximum permissible weight for HGVs only, thus it does not (for example) apply to buses.

Value

If no unit is included, the value is assumed to be in metric tonnes (unit = t, 1000 kg). See units for tagging values with units.

Additionally, the value none can be used to express that there is no weight limit. While this is default if there is no tag on a way or node and it is not necessary to tag every way with weight limit 'none', this value is sometimes required for expressing complex conditional restrictions with several exceptions.

Direction

Since the road signs in countries implementing the Vienna Convention for road signs express a "no entry" restriction, they only apply in one direction and have no effect beyond the next junction. Thus the tag should be set carefully:

  • Only set these tags on ways beyond junctions, if the restriction is valid after the junction (if there is no road sign after the junction, a vehicle making a turn at the junction but exceeding the limit is probably allowed to drive).
  • If there is no road sign on the other side of the way (or on all entries into a specific area), then it only applies to one direction. This (rare) situation should be tagged by adding :forward or :backward to the key. In most cases you find the sign on each end or every entry of an area.

Properties for expressing weight-dependent conditional restrictions

Beside the max... keys described above, it is also proposed to add following (vehicle) properties for use in conditions of conditional restrictions:

  • actualweight means actual weight of a vehicle as defined in maxactualweight
  • weightrating means rated/permissible weight of a vehicle (GVWR) as defined in maxweigthrating
  • gcweight means actual combined weight of towing vehicle plus any trailers as defined in maxgcweight (originally gcw was proposed, see updates)
  • gcweightrating means rated/permissible combined weight of towing vehicle plus any trailers as defined in maxgcweightrating (originally gcwrating was proposed, see updates).

Example: maxspeed:hgv:conditional = 80 @ (weightrating>7.5 AND 22:00-05:00) - HGVs with a maximum permissible weight exceeding 7.5t are allowed to drive 80 km/h from 22-5 at night (Note: This is a real world example from Austria, where HGVs above 7.5t registration are only allowed to drive 60 km/h from 22-5 by law unless the speed limit is explicitely increased by a road sign).

History/Updates of this proposal

2013-11-11: In Poland mappers introduced a tagging schema related to (or based on?) this original proposal (see discussion [1] and Poland road sign tagging Pl:Road_signs_in_Poland). Since the originally proposed maxgcw and maxgcwrating are used less than 10 times (several times by myself), I updated it to the widely (>1000 times) used maxgcweight and maxgcweightrating. In Poland instead of maxactualweight and maxweightrating the variants maxgcweight and maxgcweightrating are used. However, they are less commonly used and in addition there is already a significant use of the originally proposed tags. I decided to document the variants in the table, but to keep the original tags as part of this proposal.

Examples

For countries implementing the Vienna Convention

Note that countries can deviate from the convention in their law even though they have signed the convention. Please! Do not blindely tag road signs in your country with the example here without checking your local law! The convention is an agreement between countries and has - unless explicitely included in the law - no legally binding status for inhabitants.

The list is also not exhaustive, since the Vienna Convention only defines a base set of road signs and allows extensions! Especially additional panels can modify the meaning of a road sign.

ID Road sign Tagging "Official" Vienna Convention definition Comments
1 Vorschriftszeichen 9c.svg South Korea road sign 220.svg maxactualweight=5.5 NO ENTRY FOR VEHICLES EXCEEDING ... TONNES LADEN MASS [section C, II., 1(e), C,7] Applies to all vehicles including buses. The towing vehicle and trailers are evaluated separately.
  • UK: Uses road signs with addition 'mgw', see example 1b.
  • Poland, Switzerland and Liechtenstein: In these countries (at least) this sign applies to the combination of vehicle+trailer, and not truck and trailer separately as in the convention. For combinations the right tag is maxgcweight, see Pl:Road_signs_in_Poland.
1b UK traffic sign 626.2AV2.svg maxweightrating=7.5 Not defined in the convention - country specific mgw = maximum gross weight: No vehicles over the maximum

gross weight shown in tonnes. Note: Without cross-check it was assumed, just because of the title, that is applies to vehicles and not combinations.

2 Vorschriftszeichen 7a Gewicht.svg UK traffic sign 622.1A.svg maxgcweightrating:goods=X (see comment for use of maxgcweightrating:hgv) NO ENTRY FOR GOODS VEHICLES [section C, II., 1(c), C,3e]

The inscription of a tonnage figure, either in a light colour on the silhouette of the vehicle or ... on an additional panel placed below sign shall mean that the prohibition applies only if the permissible maximum mass of the vehicle or combination of vehicles exceeds that figure.

Does not apply to buses or other vehicle types except goods vehicles.

In EU countries "heavy good vehicles" are good vehicles >=3.5t (rating) as defined in access=* (class N2 and N3 starting at 12t). Thus any limit above 3.5t can be tagged as maxgcweightrating:hgv=X. A limit of exactly 3.5t should be tagged as hgv=no in EU countries.
Germany: Please see comments on example 2b and 2c.

2b Zeichen 253.svg goods=no
Germany: hgv=no
see above Buses and other non-goods vehicles are not affected by this restriction!

Germany: In addition to the convention in Germany this sign just applies to heavy goods vehicles (HGV) of class N2+N3 starting with a permissible maximum weight of 3.5t. Thus correct tagging in Germany is hgv=no.

2c Zeichen 253.svg
Zusatzzeichen 1052-35.svg
maxgcweightrating:hgv=7.5

Note: For limits below the HGV definition: maxgcweightrating:goods=X

see above Weight numbers on an additional panel mean permissible maximum mass according to the Vienna Convention.

Note that additional panels can also refer to the actual mass if explicit text for actual mass or weight is used.
Germany: In addition to the convention this sign just applies to heavy goods vehicles (HGV) of class N2+N3 starting with a permissible maximum weight of 3.5t. Thus tagging in Germany is always maxgcweightrating:hgv.

3 Speed limit of 60 for HGV with weight more than 7.5t.jpg maxspeed:hgv:conditional=60 @ (weightrating>7.5) MAXIMUM SPEED LIMITED TO THE FIGURE INDICATED [section C, II., 5(a), C,14]

To indicate a speed limit applicable only to vehicles of a permissible maximum mass exceeding a given figure, an inscription comprising that figure shall be placed on an additional panel below the sign.

The speed limit is restricted to HGVs because the additional panal also shows the silhouette of a goods vehicle and the limit is above the limit where heavy goods vehicle start (3.5t in EU countries).
4 Zeichen 277.svg
Zusatzzeichen 1052-35.svg
overtaking:hgv:conditional=no @ (weightrating>7.5) OVERTAKING BY GOODS VEHICLE PROHIBITED [section C, II., 4(b)]
  • only for goods vehicles having a permissible maximum mass exceeding 3.5 tons
  • An inscription on an additional panel placed below the sign may change the permissible maximum mass above which the prohibitions applies.
hgv and not goods is used, since the sign only applies to goods vehicles >3.5t. "Goods vehicles" with permissible weight >3.5 are heavy goods vehicle (HGV) as defined by access=*.

Germany: Germany deviates from the convention and prohibits overtaking for anyone with a GCWR>3.5t except buses and motorcars. While looking similar first, Germany disallows overtaking by motorhomes with GCWR>3.5t or motorcars with caravan trailers if (in sum) above 3.5t, which are not "goods vehicles".

5 Finland road sign 345.svg maxgcweight=30
maxweight=30 (unless signposted lower)
Not defined in the convention - country specific Finland: maximum allowed laden mass of a vehicle combination. Applies to all vehicles. Signs like depicted above with the ID '2' are not used (for clarity: 2b and 2c are used).

USA

ID Road sign Tagging Comments
US1 MUTCD R12-1.svg maxactualweight=9.1 t MUTCD R12-1
US2 MUTCD R12-4.svg max???=9.1 t

maxaxleload=1.8 t

MUTCD R12-4; Unclear if "gross" refers here to the GVWR/GCWR, since in USA "gross vehicle weight" means "actual weight" and "gross vehicle weight rating" to the permissible weight in the documents (and on the label).

Features/Pages affected

maxweight should no longer be used.

Conditional restrictions require an update: Ambiguous "weight" should no longer be used in conditions, instead the proposed properties in this proposal should be used.

Comments

Please use the talk page for comments!