Exit Info

From OpenStreetMap Wiki
Jump to: navigation, search
Available languages — Exit Info
· Afrikaans · Alemannisch · aragonés · asturianu · azərbaycanca · Bahasa Indonesia · Bahasa Melayu · Bân-lâm-gú · Basa Jawa · Baso Minangkabau · bosanski · brezhoneg · català · čeština · dansk · Deutsch · eesti · English · español · Esperanto · estremeñu · euskara · français · Frysk · Gaeilge · Gàidhlig · galego · Hausa · hrvatski · Igbo · interlingua · Interlingue · isiXhosa · isiZulu · íslenska · italiano · Kiswahili · Kreyòl ayisyen · kréyòl gwadloupéyen · Kurdî · latviešu · Lëtzebuergesch · lietuvių · magyar · Malagasy · Malti · Nederlands · Nedersaksies · norsk bokmål · norsk nynorsk · occitan · Oromoo · oʻzbekcha/ўзбекча · Plattdüütsch · polski · português · português do Brasil · română · shqip · slovenčina · slovenščina · Soomaaliga · suomi · svenska · Tiếng Việt · Türkçe · Vahcuengh · vèneto · Wolof · Yorùbá · Zazaki · српски / srpski · беларуская · български · қазақша · македонски · монгол · русский · тоҷикӣ · українська · Ελληνικά · Հայերեն · ქართული · नेपाली · मराठी · हिन्दी · অসমীয়া · বাংলা · ਪੰਜਾਬੀ · ગુજરાતી · ଓଡ଼ିଆ · தமிழ் · తెలుగు · ಕನ್ನಡ · മലയാളം · සිංහල · ไทย · မြန်မာဘာသာ · ລາວ · ភាសាខ្មែរ · ⵜⴰⵎⴰⵣⵉⵖⵜ · አማርኛ · 한국어 · 日本語 · 中文(简体)‎ · 吴语 · 粵語 · 中文(繁體)‎ · ייִדיש · עברית · اردو · العربية · پښتو · سنڌي · فارسی · ދިވެހިބަސް

motorway_link tagging best practice

There are two methods to assign exit sign information into OpenStreetMap:

  1. The collective node and way method - the exit sign information is stored on both nodes and ways
  2. The node only method - all of the exit sign information is stored on a node

The preferred approach is the collective node and way method for the following technical reasons:

  1. It can handle complex interchanges, as where a motorway_link and its associated reference number can split multiple times (such as 3A-B-C)
  2. It handles turnoffs different from a country's standard without requiring tagging exceptions (e.g. a 'left' exit in right side driving countries), meaning it is easier for data consumers to be programmed for it
  3. Associating the exit sign information with the *_link way clarifies route guidance
  4. Data consumers Telenav and OsmAnd(+) both issue route guidance using node-and-way, and do not support node-only tags (no data consumer is known to use node-only as of December 2016)

node-and-way method

The exit sign information is stored on both nodes and ways as follows:

Node
key value
highway motorway_junction
ref <junction/exit number> OR
noref yes (if no reference number exists)
name <Rarely used. Name of the indicated exit/interchange itself, not the exit's destination. Use destination tags for that, below.>
Way
key value
highway *_link
oneway yes
destination <toward location>
destination:ref (proposed) <branch route number>
destination:ref:to (proposed) <toward route number>
destination:street (proposed) <branch road name>
destination:street:to (proposed) <toward road name>
junction:ref <junction/exit number> Best practice is to always use this tag on the link way.*
maxspeed:advisory <safe exit speed> (Optional: populate when there is an advisory speed posted on ramp)
destination:symbol (proposed) <motorist services> (Optional: populate when there are motorist services located at exit)

* junction:ref is recommended on all outbound junction points from a motorway, and should have the same value of ref=* on the node. While a node provides user-readable indicators of an exit's reference as indicated, junction:ref gracefully handles routing edge cases unambiguously, such as:

  • 'left' exits in right-side-driving countries (and vice-versa)
  • Nodes where multiple exit references fork away from the same node

node-only method

All of the exit sign information is stored on the node where a link splits from the motorway as follows:

Node
key value
highway motorway_junction
ref <junction/exit number>
name <exit name>
exit_to <branch route number/road name> and/or <toward route number/road name> and/or <toward location>

Attribute Definitions

Node
Node Term Explanation
<junction/exit number> The junction/exit number from the exit sign. Examples: 236, 11A, 51A-B
<exit name> The exit name form the exit sign - this is not typical for most exits. Example from Pennsylvania Turnpike in the US: Gettysburg Pike
Way
Way Term Explanation
<toward location> The location(typically a city) that the exit/ramp/slip road will head toward
<branch route number> The route number that the exit/ramp/slip road will branch onto
<toward route number> The route number that the exit/ramp/slip road will head toward
<branch road name> The road name that the exit/ramp/slip road will branch onto
<toward road name> The road name that the exit/ramp/slip road will head toward
<junction/exit number> Populate when a exit/ramp/slip road splits at a common node and has different junction/exit numbers
Example: 51A (the node <junction/exit number> will have 51A-B)
<safe exit speed> Populate when a exit/ramp/slip road has an advisory speed sign
<motorist services> Populate when the exit/ramp/slip road has access to services motorist need

Examples

US Examples

A/B Split Example

alt text
Interstate 83 North ends at Interstate 81 exit sign

The above exit sign information shall be added to OpenStreetMap as follows:

Node
key value
highway motorway_junction
ref 51A;51B
Southbound Way
key value
highway motorway_link
oneway yes
destination Carlisle;Lewistown
destination:ref I 81 South;US 322 West
junction:ref 51A
Northbound Way
key value
highway motorway_link
oneway yes
destination Hazleton;Allentown
destination:ref I 81 North
destination:ref:to I 78
junction:ref 51B

Road name Example

alt text
Interstate 695 Outer Loop at Baltimore Washington Parkway exit sign

The above exit sign information shall be added to OpenStreetMap as follows:

Node
key value
highway motorway_junction
ref 7B
Northbound Way
key value
highway motorway_link
oneway yes
destination Baltimore
destination:ref MD 295 North
destination:street Baltimore-Washington Parkway
junction:ref 7B
maxspeed:advisory 25 mph

At the next exit, tag ref=6 on the node and destination=Linthicum destination:ref=MD 170 destination:street=Camp Meade Road on the motorway_link way.

Exit name Example

alt text
Interstate 76 West at US 15 exit sign

Exit names are usually found on toll roads. On guide signs, exit names look similar to road names. The above exit sign information shall be added to OpenStreetMap as follows:

Node
key value
highway motorway_junction
ref 236
name Gettysburg Pike
Way
key value
highway motorway_link
oneway yes
destination Gettysburg;Harrisburg
destination:ref US 15
maxspeed:advisory 25 mph
destination:symbol hospital

Issues

US Issues

Off Ramp/On Ramp Way Split

When adding interchange information to ways - please review the relationship of the interchange sign information and the connected ways. Sometimes a way will need to be split between an off ramp and an on ramp. Here is an example of when interchange information was added to a way that was both an off ramp and an on ramp:

alt text
This way needs to be split because the interchange information ( destination and destination:ref) is only for the off ramp.


Thus, leading to the following invalid on ramp directions:

alt text
The 2nd maneuver has the invalid on ramp instruction.


The above way was split - here is the updated off ramp way:

alt text
Split off ramp way.


Here is the updated on ramp with the proper interchange information ( destination and destination:ref):

alt text
Fixed on ramp way.


The on ramp instruction will now be: Turn left to take the I 99 North/US 220 North ramp toward Tyrone.

alt text
The 2nd maneuver has the fixed on ramp instruction.