Proposed Workflow

workflow.md

STEP 1: Setting up JOSM for mapping traffic data

In order to be able to map traffic data easily, there are some plugins that JOSM needs to be configured with:

• Layers to be added:

  • Mapillary layer: tms:http://d2cd86j8eqns9s.cloudfront.net/tiles/{zoom}/{x}/{y}.png
  • Bing imagery: bing[22]:http://www.bing.com/maps/

• Plugins to be downloaded:

  • Mapillary plugin for JOSM: This plugin allows the user to view mapillary images in JOSM.
  • Turn restrictions plugin for JOSM: This plugin allows to add turn restrictions to the selected roads with ease.
  • RoadSigns plugin for JOSM: This plugin offers a dialog for selection of traffic signs from a list of presets. With simple clicks you can create combinations of signs and generate tagging suggestions.

• Map-paint styles to be added:
  • traffic_signs: It displays all the existing traffic signs that have been already mapped on OSM.
  • Maxspeed: It displays the already existing speed restrictions on OSM.

STEP 2: How to use the mapillary and turn restriction plugins

Using the Mapillary plugin

• The Mapillary imagery can be added by clicking on imagery -> Mapillary in JOSM. This will add the mapillary layer over the dataset layer.

• The explanation for how the plugin works can be found here.

  Note:

  • If one is using tasking manager, first download the task from the tasking manager and then add the Mapillary layer.

• Every time a new task is downloaded from the tasking manager, a new Mapillary layer must be added after deleting the old one.

Using the turn restriction plugin

• The explanation for how the turn restriction plugin works can be found here.

STEP 3: How to add the traffic data using mapillary

• Probe the different Mapillary images present in that area to find useful traffic data that can be added to the Open Street Map.

• The Mapillary point on the GPX trail that has a red triangle along with it contain Traffic-signs.

• Probe the images to get a good idea of the surroundings and then compare them with the existing imagery to find the exact location of the traffic-sign.

  

• We need to cautious while adding a U-turn in OSM, here is how we can add it:

Note

• To get a better idea about the area/road, always inspect multiple images.
• With the help of the plugins, look for one-ways, speed-limits and traffic restrictions which are already present on the road/area.
• Unless you are sure about the start and end point of a road, it is advisable to avoid adding oneway=yes tag to it.
• We should avoid adding turn restriction to roads that are leading to oneways going in the opposite direction, like the example below. It will only result in redundant data:

Here we should avoid adding turn-restriction as it will result in redundant data

TRAFFIC SIGNAL GUIDE:

Refer to the table given below to match the traffic sign in the mapillary image against the list of traffic signs and it also consists of the OSM tags:

The last two columns of the table enlists the correct tagging convention for adding the traffic data to OpenStreetMap.

Symbol	Description	OSM Tag	Node/Way/Relation
	Speed limit	traffic_sign=maxspeed; maxspeed=*	Node/Way
	Minimum speed limit	minspeed=*	Node/Way
	No straight through	restriction=no_straight_on	Relation
	No Right Turn	restriction=no_right_turn	Relation
	No Left Turn	restriction=no_right_turn	Relation
	No Turns	restriction=only_straight_on	Relation
	No U-turn	restriction=no_u_turn	Relation
	No Left or U-turn	restriction=no_right_turn; restriction=no_u_turn	Relation
	Bike lane	cycleway=lane; bicycle=yes	Way
	No motorized vehicles	motorcar=no/motor_vehicle=no	Way
	One Way	oneway=yes	Way