Where to start….

            

The map-spat.com site divides the MAP-SPaT information into several general categories.

  1. Basic Lanes Types  (the core building blocks for all maps)
  2. Maneuvers at the Stop Line  (establishing what each lane is allowed to do at the stop line)
  3. Lane Attributes  (a rich methodology used to describe lane details
  4. Pedestrians & Crosswalk Lanes (how to capture, model and use this lane type)
  5. Shared Lane Issues (Parking Lanes, Overlapping Train Lanes, bi-directional Lanes)
  6. Geometric Projections  (the mathematical basis of how lanes are represented)
  7. Reference Map Implementations  (various example maps and worked details)
  8. ASN.1 Encoding Details   (details regarding how to encode the ASN messages)
  9. Various Industry Support Tools  (trips, tricks, and notes on various tools)
  10. Additional Supporting Resources

Note that the above links will need to be remapped once the site officially goes live.

First Steps

The first step is always the same: Get a copy of the actual standard from SAE.  Buy a complete copy, including the ASN.1 source specification here.   Then:

  • If you are entirely new to the concepts of ITS and/or DSRC, we suggest you start with…
    (cite suitable FHWA work here)
  • If you are entirely new to the concepts of MAP and SPaT, we suggest you start with…
  • If you are trying to create your first intersection MAP, we suggest you start with…
  • If you are trying to create your first intersection SPaT, we suggest you start with…
  • If you are familiar with GIS in general and need to create a MAP, we suggest you start with…
  • If you are a code developer and need ASN details, we suggest you start with…

 

While this site mostly deals with MAP creation, it will also go into SPaT and also to the high level RSU and OBU deployment details to tell people how they send or use the resulting map.  A SPaT section will be added onec more core content is done.

Preemption and Priority signal control use of SPaT (which is also the topic of the SAE J2945/11document) is not covered.

On the use of sliders

This site contains a large number of interactive graphical elements.   Many of these show “before and after” views of some aspect of DSRC MAP making.  We will also use this when the usage restrictions on some images prevent “drawing on them” with tools other than those provided by the image owner.   All of this has lead to the adoption on a slider control widget on this site.

Whenever you see a slider on a page (the orange circle with an arrow in the middle of the image gives this away), be sure to grab the arrow and slide it right and left to reveal more or less of the two underlying images.   Due to a current shortcoming in the tool, all slider images on the same page track together.  Try it below on am example reference map.

 

Credit: The widget we use is “Before After Image Slider WP” developed by swadeshswain.com

Was this article helpful?

Related Articles

Leave A Comment?

You must be logged in to post a comment.