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.

Alternative Funding for Work Zone ITS Fact Sheet

Nearly everyone who understands work zone ITS knows it is a cost-effective way of mitigating the traffic impacts of major and sometimes even minor road construction projects. Studies have proven the value of these systems. But DOTs will often tell you they don’t have the funding to pay for it.  The FHWA encourages states to use work zone ITS. They will pay for these systems through conventional construction funding. So, when states say they don’t have the funding they mean they haven’t found a pot of money outside of the money they use for asphalt and concrete.

FHWA wants to address that problem. They have just published the “Alternative Funding for Work Zone ITS Fact Sheet”. In it they document how Illinois uses HSIP funds to pay for Work Zone ITS. Download a copy of the fact sheet HERE.

FHWA says this is a highly underutilized funding mechanism. According to the fact sheet, “While some states use HSIP funds for work zone purposes, many state DOTs do not tap into this resource. Out of the more than 4,000 HSIP projects referenced in the 2016 HSIP National Summary Report, only 13 were work zone-related projects.”

Work Zone ITS Blog addressed the efforts of Matthew Daeda and Illinois DOT on May 12, 2016. We told you that this contracting method offers several advantages:

  1. The state only pays when the system is needed.
  2. They work directly with the vendor and that greatly improves communication.
  3. Staff has direct access to the system data and to make changes.
  4. By bidding for each district local companies are more likely to win, thus reducing response time.

 

This fact sheet is a BIG deal! States are always saying they don’t have the funding. This is one way of getting it. And the Feds aren’t just allowing this. They are encouraging states to use HSIP funds for work zone ITS.

States do need to identify work zone safety as a SHSP Focus Area and provide the data to support that decision. According to the National Work Zone Safety Information Clearinghouse, there were 799 fatalities in US work zones in 2017, up from the previous three-year average of 764. That’s not much when compared to the total roadway fatalities of 37,133.

But work zones are always a safety issue. States can and should include them in their Strategic Highway Safety Plans (SHSP) for a variety of reasons. Work zones force drivers to process more information and react faster than they normally do outside of work zones. That’s why crashes attributable to distracted driving, speeding, aggressive driving, and impaired driving often show up first in work zones. Furthermore, solutions that work in work zones may have applications elsewhere.

In 2017 overall fatalities declined nationally while work zone fatalities increased. Any state with this same disparity should include work zones in the SHSP. Many states have recently increased funding for road construction. They, too, will unfortunately see an associated increase in work zone fatalities. And, again, they to should include work zones in their SHSPs.

This is a wonderful tool. Thank you to Todd Peterson and Jawad Paracha for putting it together. Now we all just need to get his in front of the decision makers in our states!

 

Required Operator Training for Autonomous Vehicles?

We have talked here in the past about the difficulties autonomous vehicle drivers (operators?) will have acclimating when control of their vehicles is handed back to them, such as when they approach a work zone. Studies with simulators have shown a need for anywhere from 4 to 14 seconds for a driver to get a full grasp of all of the relevant external factors they must consider as they begin to drive.

A recent article in Axios Autonomous Vehicles points out that aviation has made use of automation for some time now. And they, too, understand the problem of moving from automated to human operators. In aviation, training focuses on that hand-off. Pilots are drilled in flight simulators on a variety of potential problems. So, when they encounter that problem during a real flight, muscle memory takes over and they react quickly and correctly.

The recent 737 Max 8 crash further underlines the importance of that training. It was apparently not included and that may have contributed to the pilot’s difficulty in regaining control.

The difference between aviation and autonomous vehicles is that training is mandatory for all pilots. If you fly a 767 you must stay current in all 767 training. However, for vehicles, a big selling point is that drivers no longer have to drive. They are told they can act more as passengers – gazing out the window, catching up on work, or watching an endless variety of streaming entertainment. Getting from that idea to one of mandatory training is a very long stretch!

Adding to the problem are the very different ways automakers are designing the machine-to-human hand-off. Each one is different.

In the Axios article, they quote Steve Casner of NASA, “We’re terrible at paying attention — and we think we’re awesome at it” Mr. Casner argues that drivers will need training. And they will need continuous updates to that training in order to learn how to deal with automation. Without initial user training and frequent refresh classes drivers will quickly become complacent.

This is a new topic of discussion but one that we must have to make CAVs safe for work zones and other segments of roadway with changing conditions.