Common Mistakes in Work Zone ITS Lessons Learned During 20 Years in This Field

Today, we would like to discuss common mistakes agencies make when including work zone ITS in a project. But we don’t want to scare anyone away or make this more difficult than it really is. Today, work zone ITS is easy to use, easy to contract, and easy to evaluate. So please dive in and learn your own lessons as you go along.

But with that said, there are a few bits of advice we can offer from our many years deploying these systems.

The first is simple enough. Before you specify a system in a project, identify and clearly state your agency’s goal for that system. Is it end-of-queue crash reduction? Is it diverting traffic onto alternate routes? Is it speed reduction? You and every other decision maker in your agency need to agree on the primary goal, and then communicate that goal to the system supplier through your specifications.

Second, don’t try to do too much with your system. Focus on that primary goal first. If the system supplied can also handle additional responsibilities, then add those that help you meet any secondary goals. For example, a queue detection system can also provide traffic data to meet the Federal Work Zone Safety & Mobility rule. But don’t add features that will just bombard you with data you can’t use. You will have plenty to work with as it is.

Once you have your goal for the project, you can begin designing your system. If the goal is reducing rear-end crashes in slow and stopped traffic, doplar radar is the best sensor to use. It works well at low speeds and is inexpensive. But if your goal is to replace a permanent system that measures speeds, counts and classifications, a side-fire radar such as Wavetronix or RTMS.

Next choose your sensor locations. For most systems you will space them about three-quarters of a mile apart. You may get away with as much as a mile or more in some situations, but more often you will want them between a half-mile and a mile apart. Once they are in place and collecting data, check that data to be sure it is what you need. Locations with a lot of concrete barrier sometimes result in radar echo giving you false results. Locations such as a gore point at the on-ramp from a truck scales will result in below-average speeds as trucks slowly speed up onto the mainline.

Budgets often force you to limit the scope of your system. If it comes down to a choice between cameras or more sensors, please consider maximizing the number of sensors. Better, richer data will result in a more responsive system, and one less susceptible to service interruptions. If you must have cameras, limit their use and the video frame-rate to keep your wireless expenses lower.

Your specifications should include the type and quantity of sensors, message signs, camera trailers and other devices. And consider including a line item for each type of device. In that way, you will have a price if you find you need to increase or decrease the quantity of devices.

Finally, dig into your data. Learn what makes the system work. When an incident happens, look at the data to learn how quickly it affected traffic upstream. And how quickly it clears once the cause has been corrected. This will give you a better sense of the capabilities of these systems and how best to use them on future projects.

New Open Source AV Visualization Tools May Aid Our Industry

One of the challenges the roadway safety infrastructure industry faces in regard to autonomous vehicles is understanding how those vehicles visualize the world they are passing through. Manufacturers have been restrained in their sharing of that information. The best we can get out of them is “Keep doing what you are doing to make striping, signing and traffic control devices easier to see.”

But a story published yesterday in The Verge by Andrew Hawkins details efforts by GM Cruise and Uber to make some of those visualization tools open source and free to use. It is even provided in a fairly simple and easy to use format that anyone can use on most any device.

 

This could be very useful for pavement marking manufacturers or contractors. It may be helpful for sign manufacturers. And it will definitely help traffic control device manufacturers understand what the vehicle “sees” and what it does not.

Now this is far from the ultimate testing platform, but it will help our industry begin to develop an understanding of the underlying issues and ways we may be able to address them. It may also help work zone ITS providers in that it offers a simple data formatting system that may be able to accommodate data feeds from smart work zones.

The GM Cruise tool is called “Worldview” and can be found HERE.

The Uber tool is called “Autonomous Visualization System” or AVS for short and can be found HERE.

We haven’t spoken with anyone who has used these tools yet. So, please try them out and tell us what you think. Are they useful to our industry? And, if so, how? What can be improved? We look forward to hearing from you!

 

Drivers Recognize the Importance of Connected Work Zones

We have been talking for the past couple of years about “connected work zones” – that is, the automatic and real-time method of putting our work zones on the digital map that everyone is quickly coming to depend upon when choosing a route.

We have argued that traffic control workers don’t need more to do when they are setting up or tearing down a work zone. So, to arrive at a point where we have timely and accurate reporting of work zones, it must happen automatically.

Several companies are now providing solutions. Those solutions vary in their complexity and technologies involved. But in their simplest form they each include a device attached to existing traffic control devices. One of those is normally the arrow board. The beauty of this approach is that when the arrow board is turned on, the system immediately tells the digital map that a work zone just popped up on that route at that precise location. And when it is turned off, it tells the map that the work zone is now gone. It happens every time a “smart” arrow board is used and those are becoming more and more common.

We all “get” this. But now the driving public is also recognizing the importance of these systems. An article by Tim Harlow in the January 27th Minneapolis Star-Tribune talks about a system supplied by Street Smart Rentals to Minnesota DOT in the Twin Cities.

He points out that the existing 511 system does a good job of informing the public about long-term projects, but that short-term and unplanned closures can cause just as much disruption yet are not included in their warnings to the public.

The system supplied by Mike Granger and Street Smart Rentals is changing that for the better. And with the arrival of autonomous vehicles, this will become even more important. In the article Brian Kary, MnDOT’s Director of Traffic Operations “said the technology is not active now, but it could be this summer or fall. MnDOT is evaluating costs before making it a permanent 511 feature. The agency also is setting up a timeline install the technology and figuring out how best to get information to other traffic information sources, such as Google, Waze and TomTom, since not everybody uses 511.”

We believe economies of scale will quickly and significantly reduce those costs. And the need for this information will bring down any barriers to those traffic information sources. We look forward to hearing more about this system and others like it the exciting year to come.