Introducing the new-and-improved ODOT SpeedMap

After many months of development and testing, the new-and-improved Oregon Department of Transportation (ODOT) TripCheck SpeedMap has been rolled out. Sort of. It’s currently on the What’s New page of TripCheck, where ODOT is previewing it for the public and gathering feedback. Please check it out and let ODOT know what you think (we’d really like to know as well…)!
We aren’t just interested because we’re map geeks. We developed the application. It’s a unique and “first ever” application in many respects.

Map for the Color Blind

For starters, it’s the first traffic map to provide a grayscale option for those who face the challenges of color blindness. With close to 9% of the population being color blind in some way, ODOT wanted to make sure that the entire traveling public would be served by the new map. The Gartrell Group started with a fair amount of research into the issue of designing web sites and mapping color schemes for people with Color Visual Deficiency. We initially proposed developing the map using a color blind friendly color palette, so that users would not have to toggle between maps, but ODOT felt that the majority of the traveling public has become conditioned to understand what the green, yellow and red colors indicate. I can’t say I disagree!

Blend of Technologies

As you will no doubt notice, the map is zoomable and pannable (if those words don’t already exist, I just made them up…). The old map was most certainly not. To achieve this feat – and maintain the needed performance – we are using a hybrid GIS approach. A server running ESRI’s ArcGIS Server 10 is capturing the speeds from each of the segments, at each of the zoom levels, for both the color and grayscale maps, and placing the corresponding color on the matching highway segment. An image of each zoom level is then sent to the SpeedMap web server every two minutes where they are compiled and turned into the interactive SpeedMap. This allows the travelling public to get virtually live traffic conditions without bringing the server to its knees.

Extremely Accurate

Traffic-flow maps aren’t anything new. They’ve been available from Google for a while, and people can even add traffic speed services onto their car’s GPS. The difference is in the data. The Google/NavTech solutions depend upon estimating speeds based upon mobile phones constantly triangulating their position. Yes, your phone is telling the world where you are and basically how fast you’re going! The ODOT SpeedMap uses data derived from in-road and roadside sensors and are far, far more accurate than any of the alternatives.


Like every project, this one had its challenges. Technology was the biggest challenge; how do we deliver the type of map that web users are accustomed to without bringing down the infrastructure that serves it? Our unique solution is able to deliver the experience that savvy web users expect while maintaining the performance requirements that ODOT expects.

A screenshot showing the highway speeds and the toggle to turn them on and off.Our other challenges revolved around data and how (and when) to display it. Being the fans of simple, clean maps, that we are, we made the case for a simple, thematic map, free of distractions. Our clients, being engineers and fans of data, wanted to show the underlying data. Their thoughts; “we have the data, let’s show it.” It’s hard to argue with that rationale! This results in a number being placed next to each highway segment, and, in my opinion, a very, very busy map. I pleaded with our clients, but they insisted that the numbers should stay. We reached a compromise with the “Speeds On/Off” toggle. This allows users who don’t want to be distracted by all of the numbers the ability to simply turn them off.

The final result is a revolutionary map that we hope will serve the traveling public with the information that they need when they need it, and is something that everyone at the Gartrell Group is proud to have worked on!