Exit Numbers Workflow.md

Detailed Workflow of adding missing Exit numbers in USA

Assign an area

1. Assign a state to yourself in spreadsheet

Assign a highway

1. Open the exit number reference document for your area. Pick a highway to check and assign it on the spreadsheet

2. Browse autopista to your state and click search in map to load the visible highways. Select the highway from the list.

Verify the exits on the route for missing information

1. Load the route in JOSM

2. Add the motorway exit reference tms layer in JOSM

3. Browse along the route and check the ways on both directions at every exit location for the following:

• There is a motorway_junction at the start of every motorway_link exiting the highway red dot on the the tms layer
• The motorway_junction has a correct exit number ref value as per the source. Points with missing ref tags represented by a blue dot in the tms layer
• The exit number on both directions are the same
• There is only one exit in a direction for every exit number

Add missing exit numbers

1. Download the data and mapillary layer to locate a signboard around the blue marker in the imagery.

2. Use a combination fo Mapillary, TMS layer, Department of Transportation (DoT) documents and Wikipedia to add the ref=* tag on highway=motorway_junction (stick to using Mapillary and DoT doc as primary source and move to others in case of unavailablity of information)

3. If it is confirmed there is no exit number for the motorway_junction add another tag noref=yes to indicate the exit does not have an official reference number.

Analyzing signboards in mapillary

Look out of Highway sign boards on imagery. They may look something like this-

Places to look for-

• near a motorway_junction
• near start of a motorway_link

Do's and don't

• It is not necessary that exit numbers are sequential. Yoy might find 45 after 41.
• There are some motorway_junction which don't have any associated exit number. Add noref=yes on these nodes.
• In the case of discrepancy between mapillary and DoT document, look out for the recent change in exit numbers on the web. Many states changes/in a process to change the exit numbers.
• Ignore the highway=motorway_junction where the traffic flow is towards the motorway