The Automated Vehicles Symposium from a Work Zone Perspective


The Work Zone ITS Blog attended the Automated Vehicles Symposium in San Francisco July 20th. We came away with a very positive impression of the state of this practice. In previous posts we have expressed a concern that autonomous vehicle (AV) design must take work zones into consideration early in the process. That now appears to be the case. Work zones were mentioned in many of the plenary sessions along with the need for their systems to operate safely within them.

Breakout Session #20 – “Physical Infrastructure, Work Zones, and Digital Infrastructure” discussed this issue in more detail. Ross Sheckler of iCone explained the special problems inherent in work zones. We will get into his presentation in more detail in a future post, but he opened a lot of eyes. Audience members were asking questions, taking abundant notes, and were otherwise very engaged in the topic.

This means, of course, that we have their attention. It is good that we as the work zone industry have gotten involved. Now we need to make the most of it by making ourselves heard in this and other AV events.

As you may be aware, there is still a lively debate over two topics: 1) DSRC versus 5G communications, and 2) Whether automakers should include level 2 automation in production vehicles. Both of these topics are important to the work zone industry.

Let’s start with the communications issue. 4G is the digital wireless network you already use for your smart phone.  This is what we use today to control message signs and to upload portable sensor data.  A faster version known as 5G is rolling out in many areas. DSRC or Dedicated Short Range Communications is a radio spectrum (5.8 ghz) set aside, at least for now, for the exclusive use of the transportation industry. DSRC is faster and doesn’t have the latency problems associated with 4G. Vehicle to vehicle warnings occur instantly so if a car tells the one behind it that it is about to stop, the one following will get that warning soon enough to stop safely as well.

For most work zone applications 4G/5G works just fine. So manufacturers will likely stick with that. But if DSRC becomes more popular changes to our systems may become necessary. Work zone system designers should take this into consideration.

Level 2 automation is more of a problem. It is a suite of systems including adaptive cruise control, lane keeping, etc. that allows drivers to relinquish control for a period of time, say as they are driving on a freeway from one town to another.

The Tesla driver killed recently was using level 2 automation. He died when his car ran under a big rig turning in front of him. But he could as easily have run through a work zone. So this stage in automation must relinquish control automatically when approaching work zones. And it must do so early enough for the driver to take control and drive for enough time to regain his or her situational awareness. Human factors studies are just beginning to look at this, but it is clear this may take a minute or two. So on freeways, control would have to switch to the human driver at least two miles prior to the work zone.

How this will be accomplished is not yet clear. If all work zones are logged in real time into a central database such as a travel time system, it could be used to toggle control. Or perhaps a device mounted in the first message sign (normally located a couple of miles upstream of the work zone) could do the same thing.

These are all important and must be settled before AV technology can become mainstream. Events like the Autonomous Vehicle Summit will help move these conversations forward. So get involved and ensure that work zones are part of the discussion.

Will Pokémon Go Kill DSRC?

PokemonIf you have been paying attention at all during the past few days you have heard about the new game Pokémon Go. It is what is called an augmented reality game. It is wildly popular. Tens of millions have already downloaded the game in its first week. They wander around looking at a Google Earth image of their location that allows them to see and perhaps capture mythical creatures known as Pokémon.

What I found interesting is that the game is written. It works fairly well and will only get better with time. It is available in both iOS and Android versions. This will be a huge boost for 4G/5G V2X communications and may be a nail in the coffin for DSRC.

Think about it! Instead of Zubats, Pidgey, or Paras (varieties of Pokémon), imagine placing work zone devices in this virtual reality. Virtual cones and arrow boards would mark the exact spot where a work zone taper begins. Message signs could display the messages currently displayed on the corresponding message signs in the real world. And all of that information could be displayed in real time in vehicles approaching that location.

This could also be done in what you might call the opposite direction. Augmented WorkzoneA traffic control technician could be sent into the field with his S7 Android phone. Once he gets to the work area he wakes up his phone, clicks on the work zone app, and a Google earth image of what he is looking at in the real world pops up. But that image shows the work zone already set up. It might show the messages for the message signs. It would be very easy to place each advance sign where it belongs. Just look at the buildings, trees, etc on the virtual display and place the ROAD WORK AHEAD sign in the real world where it shows on the virtual display.

Traffic control plans would become a virtual reality file that designers would use to fit their plans to the real world conditions. Once done, it should work perfectly in the real world. It is like Computer Aided Design/Computer Aided Manufacturing – what you draw is what you get!

But I digress from my earlier point and it is an important one. Augmented reality is here. It is working on digital phones on 4G networks. There is no reason to start over again and do the same thing for DSRC. Granted, there are some applications where latency is an issue, like warning the vehicle behind you that you are about to stop, where DSRC still has advantages. But, thanks to Pokémon Go, I don’t believe infrastructure features such as we will need for work zones, will be working through DSRC.

Why Aren’t Queue Warning Systems Used On Every Project?

Those of us that have been in the work zone ITS industry for several years understand that agencies don’t change quickly. New technology must be tested and evaluated before it is used on a more regular basis. We get that. But we are now at the point where queue warning systems should be included on every project where frequent and dynamic queuing is expected.

WZcrashesStudies by the Texas Transportation Institute have shown a reduction in rear end crashes of as much as 45%. Crash severity is reduced as well. Other states including Illinois have also seen a dramatic decrease in crash frequency and severity.

These systems are inexpensive and the benefits are substantial. Avoid just one lawsuit by using queue warning and that savings will more than pay for the cost of the system. So it does not matter how long the project lasts. Projects lasting only a few days could deploy a system for something like $700 per day.Projects months long would pay something like $10,000 per month. Those prices include the sensors, message signs, communications costs, design, set-up, etc.

One law suit will cost tens if not hundreds of thousands of dollars.  It really is that simple. And that doesn’t take into account all of the other benefits. Fewer crashes mean the project is completed faster. Motorists are happier with the DOT because they aren’t experiencing long delays. And you will have the data to meet the Federal Work Zone Safety & Mobility Rule requirements for work zone performance measurement.

There has been progress. Texas is moving toward statewide use of queue warning systems. Illinois is also. Several other states are working on following suit. But most states only use them on special high impact projects. Some don’t use them at all.

So, I really do want to know. What is holding you state folks back? Why don’t you use these everywhere? I sincerely want to know. Please comment on this post. Let’s talk about it. Perhaps as a group we can find ways around the road blocks you face. And together we can significantly reduce the single largest cause of work zone fatalities nationwide.

Portable Traffic Signals as Work Zone ITS?

20160623_065843Today there are many definitions of work zone ITS. I’ve always felt that just because a device is controlled by electronics and some amount of internal software, does not qualify it as work zone ITS. Good examples are portable changeable message signs or portable traffic signals. In their simplest form they work independently and do not react to their environment.

But recently we started a project with portable signals that should qualify. Before the job bid we suggested portable signals as a cost-effective alternative to hardwired temporary signals mounted on posts and powered by a generator. The agency agreed but asked for most of the optional features mentioned on Horizon’s website. Those included wait time display, drive way assistance device, emergency vehicle preemption, and remote monitoring and notification.

Let’s look at each of these in a little more detail.

The wait time display is a changeable message sign attached to the articulating arm of the signals. When the signal at the other end of the work zone is green, the one facing stopped traffic tells it the maximum time they can expect to wait. Then, once the signal on the other end goes to red, it displays a countdown to green equal to the remaining clearing time.

This is a great feature when the work zone is especially long or when drivers on one end of the work zone cannot see the other end. Like travel time systems, once drivers know what the wait time is, they don’t seem to mind it as much. But not knowing often upsets them.

20160623_065949The driveway assistance device is another clever addition. The display consists of a red light and two flashing red arrows, one pointing right and the other left. When the light is red, drivers are expected to stay put. But when the right arrow is flashing, they can turn right when it is clear. The device ties into the signal phases on the main line. The system knows when traffic is moving to the right and tells the driveway assistance device to inform any drivers there that they may do so, too. It’s similar to a WAIT FOR PILOT CAR sign, but starts the moment traffic is cleared to go in that direction.

Emergency vehicle preemption is the same as most permanent signals use. It immediately turns the signal on the other end red, but still must give the same clearance time before turning to green for the ambulance or fire truck. Because these signals are farther apart, sometimes a half mile or more, the emergency responder must still sit there until traffic clears. Otherwise the potential for conflicts exists. This is one feature I would not recommend again, except when the signals are set up for a conventional intersection where clearing time is minimal. Or when there is an especially high volume of traffic that would otherwise extend the green time without preemption.

Remote monitoring is just what it sounds like. The signals report to a server over a wireless digital modem. All aspects of signal operation are monitored. If a lamp fails, or power drops, or communications between signals are lost; an alarm is sent to everyone concerned via text or email. Signal operations are also logged with each phase date & time stamped. So if a motorist claims they were green when they were actually red, the agency would be able to prove that.

Traffic engineers have taught drivers to expect traffic signals to do certain things. Portable signals can now do anything that permanent ones can do. That reinforces those lessons and makes our work zones safer.

Adapting Existing Technology to Unusual Traffic Problems

The work zone ITS industry has produced many creative ways to help mitigate the impacts to traffic from work zones and to protect workers from that same traffic. But often the problems we solve aren’t the same ones we set out to address. This is true for most industries when they encounter new technology.

According to author H. W. Brand it was true for the movie industry as well. When the first “talkies” were released, “Sam Warner (of Warner Brothers’ fame) convinced his brothers to purchase a technology that allowed the attachment of sound to recording film.” “The initial appeal was that sound would permit theaters to dispense with the orchestras that played accompaniment to otherwise silent films.” Today we can’t imagine movies without the sounds of explosions, gun fire, and, of course, dialogue.  But they were focused on the economic benefits of the technology and so missed what we all see as the obvious artistic advantages.

The same is often true in our industry. Our technologies are more mature now, though new ideas are introduced every day. But too often we miss good opportunities to improve the safety or efficiency of our roads because we don’t have a prepackaged system ready to deploy.

In fact, we do have them ready. We just don’t think it through far enough. Most of our systems use sensors to measure traffic flow, then compare that data to a set of rules, which then trigger outputs like messages to message signs, or alarms at a traffic management center. So it does not matter what your traffic concern is, a system can probably be created to address it. And while such a system could be called “custom”, it won’t normally be saddled with the costs and lead times normally associated with custom systems.

Redding Map

A good example was a demo project done for Caltrans a few years ago. They were closing one of their busiest ramps in Redding for reconstruction. The plan called for them to send traffic to alternate ramps. But no one of those was capable of handling the volumes at the closed ramp. Road-Tech proposed a simple solution. A sensor was placed on each of the alternate ramps. And portable changeable message signs directed traffic to the best alternate. As traffic backed up on the first alternate ramp the sensor detected the stopped traffic. That caused the system to change the message signs to recommend the second alternate ramp. If that ramp backed up traffic was sent to a third alternate ramp.

It was simple, inexpensive, and worked very well. The only problem encountered was public outreach efforts scared everyone away. So the volumes were never as high as expected. But this does show what can be done with the tools we already have. No one talks about alternate ramp systems. But it turns out we had one ready to go. We just didn’t know it.

Next time you are faced with a traffic problem, try to imagine a rule. That rule would say, “If traffic does X, make Y happen.” So if traffic slows I want to change the message signs to warn of STOPPED TRAFFIC AHEAD. Or if average traffic speeds exceed 75 MPH, I want to send an alarm to the police department. If you can come up with a rule, a solution is probably already available. Keep that in mind and you’ll be surprised what can be done!

The Illinois Model for Procurement of Work Zone ITS

Yesterday I had the pleasure of sitting in on yet another Smarter Work Zones webinar from the Every Day Counts folks. This was lucky number 13 in this wonderful series and looked at procurement of work zone ITS. You can download the recording in a few days at:

Early in the webinar an attendee, Charles Martin, made a statement in the chat box that I thought helped focus the discussion. I believe he once worked for Maryland SHA and that experience and perspective showed through when he said, “I find that the most complicated issue to determining how to fund adding SWZ’s often it is not one project driving the need, but rather several. One may have Fed-aide, and others may not. (N)one of the projects may have funding to add ITS.”

The webinar that followed may not have answered his concerns completely, but it did offer several innovative options that should work in most situations.

Todd Peterson of FHWA began by giving an overview of procurement methods and explained that the best option depends on the type of work zone ITS you plan to use. Jerry Ullman of Texas Transportation Institute (TTI) ran through the different contracting methods that three states (Massachusetts, Texas and Iowa) have used and shared some lessons learned. Finally, Matthew Daeda of Illinois DOT went into detail on his state’s approach and that’s what we will talk about today.

Illinois uses a two level approach to procurement of work zone ITS. For larger contracts and longer term projects they try to identify the need as early in the process as possible. This is usually accomplished as a lump sum line item in the bid documents. Details regarding the types and quantities of devices are included in the special provisions. When they know they will have serious traffic impacts, they include WZITS and other mitigation strategies in the bid documents.

They will also add WZITS under change order when impacts are greater than expected. Again this is done with the same language they use when it is included in the bid.


But for smaller projects and short duration traffic impacts, they are now using an on-call contract. Each district advertises a bid for this on-call service. Districts 1, 8 and 9 already have three year contracts in place. Districts 2, 3 and 5 have or will soon have contracts in place. Districts 4, 6 and 7 will follow suit very soon. The on-call work zone ITS is paid for using HSIP funding.

These on-call contracts are intended to provide queue warning for projects with a duration of two weeks or less. In District 1 (Chicago) and 8 (St Louis) the vendor supplies 4 changeable message signs and 4 sensors. In more rural District 9 the vendor supplies 1 changeable message sign and 4 sensors. Each district adjusts the quantities to fit the needs of that district. District 9 includes rates for monthly rentals. Districts 1 and 8 only include daily and weekly rates.

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.

Mr. Daeda offered several lessons learned. He said that one vendor installed software in their TMC that did not work well with their firewall. In the future he would like to require vendors to install and test any software before getting a notice to proceed.

He would like a pay item for supplemental devices. Then he could add more sensors or message signs when they are needed.

When deployments run over a month, they currently pay for a month at the monthly rate and for additional days beyond that at higher daily and weekly rates. Mr. Daeda wants to change that going forward to be at a percentage of the monthly rate once the system has been out for more than a month.

Matthew plans to clarify language regarding relocation of devices. And there have been times when he wished he could add camera trailers.

In our last blog post, “The State of the Work Zone ITS Industry”, we talked about the many ways in which 2015 was a landmark year. This webinar is a perfect example of that. These EDC events just keep getting better. The speakers were all on topic and very professional. The webinar service worked without interruption. And the attendees asked great questions.  If you haven’t watched them yet, you are missing out on a great experience!

The State of the Work Zone ITS Industry

We are starting a new construction season so I thought it would be a good time to review our progress as an industry, look at where we stand today, and talk a little about prospects for this coming year.

2015 was an important year for all of us. It was in 2015 that we began to get good hard data to support the value of work zone ITS. The Texas Transportation Institute led the charge with their My35 queue warning system research. Their data is not final, but it is clear that use of a queue warning system has reduced end of queue crashes by as much as 45%. It has also significantly reduced the severity of the crashes that do still occur. We have always known these systems are effective. Now we can prove it.

Illinois DOT has shared data from work zones on a stretch of interstate under construction two years in a row. The first year a queue warning system was not used. The second year one was used. In that second year the work zone was in place for a longer period of time, yet they saw far fewer end of queue crashes just as they did in Texas.

This data will result in much greater use of end of queue systems. Another effort that is helping is the Every Day Counts initiative from FHWA. They just completed webinar number 12 of the Smarter Work Zones series. This focus on proven work zone ITS and how to deploy it has done wonders to promote these life saving technologies. You can view any of these webinars now at: .

More good news came on the procurement front. Agency design folks have passed up work zone ITS in the past because they didn’t know how to write it into their construction bid documents and didn’t have the time to figure it out. But now states like Texas, Iowa and Illinois have shown us the way with innovative on-demand contracts for queue warning systems. This allows the traffic operations folks to use these systems when and where they are needed. Including systems in large jobs still makes sense, but this on-demand method allows far greater use on smaller jobs where traffic impacts were not clear before the job was let. Many other states are now adopting this model including Indiana, Michigan and North Carolina.

As more and more states begin to use work zone ITS, the resulting data can be used to prove the value of these systems once again. And that will push even more states to follow suit.

In the meantime, we are seeing help from another, unlikely source: the autonomous vehicle industry. Discussions at autonomous vehicle events between their designers and work zone ITS practitioners have shown great potential for collaboration going forward. They now understand they need to know where work zones are located in real time and they are interested in how we can help them do that. Don’t be surprised if we hear several big announcements on this subject in 2016!