Exit Info

Methods

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

1)The collective node and way method - the exit sign information is stored on both nodes and ways as follows:

Node

key	value
ref	<junction/exit number>
name	<exit name>

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> (Optional: populate when a ramp splits and has different exit numbers – such as 51A and 51B
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)

2) The node only method - all of the exit sign information is stored on a node as follows:

Node

key	value
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>

Preferred Method

The preferred approach is the 1st method – the collective node and way method for the following reasons:

1. It can handle complex interchanges. Especially in the US where an exit ramp can split multiple times such as 3A-B-C
2. Associating the exit sign information with the *_link way improves route guidance
3. Germany has widely populated the ref and destination of the *_link way with junction/exit sign information

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

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

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
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

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:

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:

The 2nd maneuver has the invalid on ramp instruction.

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

Split off ramp way.

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

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.

The 2nd maneuver has the fixed on ramp instruction.