udot’s methodology in creating nmap files dot... · 2019. 2. 19. · • the manual workflow...

Chuck Felice

Utah Department of TransportationFebruary 14, 2018

Creating Road Intersection MAP Data for MMITSS

“ The NMAP File”

UDOT’s Methodology in Creating NMAP Files

• An ASCII text file which contains intersection map data required by MMITSS

• MMITSS uses NMAP files to create J2735 MAP Messages

• Components of the NMAP File

• Intersection Information

• Identification Number

• Intersection Attributes (bit field definitions)

• Reference Point (latitude, longitude)

The MMITSS NMAP File

• Components of the NMAP File (cont’d)

• Approach Information

• Number of Approaches in the intersection

• Approach Type (approach or an egress)

• Number of traffic lanes in the approach


• Components of the NMAP File (cont’d)• Traffic Lane Information

• Lane identification number• Lane type (numeric value 1 – 5, 1 = motorized vehicle lane)• Lane attributes (bit field definitions)• Lane width (centimeters)• Number of lane nodes for a specified lane• Lane node coordinates (latitude, longitude)• Number of connected lanes• Connected lane identifiers



MAP_Name 4610SouthRedwoodRoadReduced.nmapRSU_ID 4610SouthRedwoodRoadIntersectionID 7605Intersection_attributes 00110011 /* elevation: Yes, lane width: Yes, Node data 16 bits, node offset solution: cm, geometry: Yes, navigation: Yes */Reference_point 40.6698353 -111.9388660 13110 /* lat, long, elevation (in decimeters) */No_Approach 8Approach 1Approach_type 1 /* 1: approach, 2: egress */No_lane 2Lane 1.1Lane_ID 1Lane_type 1 /* 1 to 5, for this intersection all 1: motorized vehicle lane */Lane_attributes 0000000000101010 /* Approach path, straight permitted, right turn permitted, no u-turn, turn on red, */Lane_width 365 /* in centimeter = 12 feet */No_nodes 21.1.1 40.6698529 -111.93866331.1.2 40.6698459 -111.9369704No_Conn_lane 26.1 4 /* Lane 1.1, Straight ahead */8.1 3 /* Lane 1.1, Right turn */end_laneLane 1.2Lane_ID 2Lane_type 1 /* 1 to 5, for this intersection all 1: motorized vehicle lane */Lane_attributes 0000000001010100 /* Approach path, left turn permitted, yield, u-turn allowed, no turn on red */Lane_width 305 /* in centimeter = 10 feet */No_nodes 21.2.1 40.6698201 -111.93866371.2.2 40.6698190 -111.9384932No_Conn_lane 14.3 2 /* Lane 1.2, Left Turn */end_laneend_approach..end_map

• “MMITSS Final ConOps Applications User Guide” – University of Arizona and others, Version 3.0, October 21, 2012

• “MMITSS Field Applications User Guide” – University of Arizona, Version 1.0, July 7, 2015

• “Signal Phase and Timing and Related Message Binary Format (BLOB) Details” –FHWA Office of Operations Research and Development, Draft February 17, 2012

• An example of a NMAP file – MMITSS Source Code Configuration Files directory

Documents Referenced for NMAP File Creation

• ESRI ArcMap GIS Application

• Google 6 Inch per Pixel Satellite Imagery (validated by field surveys)

• Microsoft Excel

• Notepad++ file editor (solution for carriage/line feed character issue)

• NMAP File Parser / Validation (C++ application)

Software Tools and Imagery used in NMAP Creation

• Create road intersection reference point and lane nodes in ArcMap using Google imagery.

• Export reference point and lane node data and coordinates (latitude, longitude) to a Microsoft Excel worksheet.

• Add additional road intersection information to spreadsheet required for NMAP file format.

• Transfer data from worksheet to NMAP file (NMAP file is created by and edited within the Notepad++ file editor).

• Validate the NMAP file by processing it with the NAMP Parser / Validation application.

• NMAP file is now ready to used by the MMITSS software.

NMAP Creation Workflow


Microsoft Excel NMAP Worksheet


MAP_Name 4610SouthRedwoodRoadReduced.nmapRSU_ID 4610SouthRedwoodRoadIntersectionID 7605Intersection_attributes 00110011 /* elevation: Yes, lane width: Yes, Node data 16 bits, node offset solution: cm, geometry: Yes, navigation: Yes */Reference_point 40.6698353 -111.9388660 13110 /* lat, long, elevation (in decimeters) */No_Approach 8Approach 1Approach_type 1 /* 1: approach, 2: egress */No_lane 2Lane 1.1Lane_ID 1Lane_type 1 /* 1 to 5, for this intersection all 1: motorized vehicle lane */Lane_attributes 0000000000101010 /* Approach path, straight permitted, right turn permitted, no u-turn, turn on red, */Lane_width 365 /* in centimeter = 12 feet */No_nodes 21.1.1 40.6698529 -111.93866331.1.2 40.6698459 -111.9369704No_Conn_lane 26.1 4 /* Lane 1.1, Straight ahead */8.1 3 /* Lane 1.1, Right turn */end_laneLane 1.2Lane_ID 2Lane_type 1 /* 1 to 5, for this intersection all 1: motorized vehicle lane */Lane_attributes 0000000001010100 /* Approach path, left turn permitted, yield, u-turn allowed, no turn on red */Lane_width 305 /* in centimeter = 10 feet */No_nodes 21.2.1 40.6698201 -111.93866371.2.2 40.6698190 -111.9384932No_Conn_lane 14.3 2 /* Lane 1.2, Left Turn */end_laneend_approach..end_map


NMAP File being edited in Notepad++


NMAP File Validation

Small Road Intersection

Large Road Intersection

• Good informative documentation is a must. A lot of time was spent determining what needed to be in the NMAP file: where information for the attribute bit field attributions could be found; how many lane nodes should be created for each lane; and other “gotcha’s”. Searching on the internet was done to obtain the above mentioned information along with making phone calls to people. Better documentation could have solved these problems and lessened the learning curve on how to create a NMAP file.

• NMAP file size is limited to approximately 1300 bytes. This limitation is due to the message packet size being sent from one DSRC radio to another DSRC radio. This size limitation issue required the number of lane nodes to be kept at a minimum. Future MapData compression algorithms should reduce these size limitations

• The manual workflow process has given insight into how the process could be sped up using software to automate some of the tasks in creating a NMAP file.

• Intersections under construction.

Lessons Learned

Road Intersection under Construction

• Best Practices Guide for collecting intersection geometry.

• Best Practices Guide for creating MAP Data.

• Methodology for automating MAP Data messages / files.

• Validation of MAP Data Messages / files.

• Human readable form of MAP Data (XML / JSON).

Future Needs

Questions?