Work Zone Traffic Control “Down-Under”

We just returned from a wonderful trip to Australia where we spoke to the Traffic Management Association of Australia (TMAA) about work zone ITS. Their members were all excited and focused on finding safer, more efficient ways to manage their work zones.

The program was packed full of interesting speakers and a variety of timely topics. They also gave us all just the right amount of time to discuss those topics between sessions. It was very well run.

The attendees seemed to enjoy talking to Americans and all asked what we thought of the meeting. My first answer was always the same: traffic control companies in both countries share the exact same set of problems:

1) Speeding in work zones.

2) End-of-queue crashes.

3) Hiring, training and retaining good employees.

4) A perception by the driving public that we are there to make their lives miserable.

5) Insufficient funding for maintenance and construction.

6) Changing standards and levels of enforcement from one state to the next.

7) Varying commitment and funding levels from one state to the next.

Just like ATSSA, the TMAA brings contractors, manufacturers, academia and government agencies together to discuss these problems and identify solutions. The TMAA does an especially good job of this. We look forward to learning more from them in the years to come!

Work Zone Reporting to Autonomous Vehicles

We just returned from ATSSA’s Midyear meetings in Louisville, Kentucky. The Innovation Council meeting was well attended and included several very interesting speakers. Many topics were discussed but the real focus of these discussions, both during and after the meeting, was autonomous and automated vehicles and how our members can best prepare for them.

Speakers including Dr. Paul Carlson talked about the importance of signs and pavement markings bright enough to be seen and recognized by automated vehicles. AV manufacturers have stated that this is the most important thing we as an industry can do to prepare, at least from the autonomous vehicle perspective.

But from a stakeholders’ perspective – specifically work zone safety – many wonder how autonomous vehicles will know where work zones are located and what they will encounter as they drive through them. This blog has discussed this subject several times over the past few weeks, but given the interest in Louisville, it seemed a good time to review all of the likely ways in which this will be accomplished and consider the advantages and disadvantages of each.

There are at least 6 ways to do this. And by “this” we mean update digital maps in real time. First we must tell everyone where work zones are active. That’s the most important part. For by telling them, those autonomous vehicles can then trigger a return of control to the driver well before the vehicle enters the actual work zone. But ideally, these systems will also include information about that work zone including which lanes are closed, prevailing speeds, and geometric changes including lane shifts, narrow lanes, etc.

So, in no particular order, these are the more likely ways of getting that information out in real time:

Traffic Control Device Automated Reporting

Devices including arrow boards, traffic sensors, flashing beacons, and stop/slow paddles can be equipped to report to a traffic data service or DOT website. This is already being done today. When the device is turned on, it reports its GPS coordinates and the type of work zone. For example, an arrow board, when turned on would report a lane closure. When it is turned off, the device reports the work zone is no longer active.

The advantage of this approach is the activity is truly reported in real time without human input. Another advantage is the location will change as the equipment moves, say for a paving or crack sealing operation. The disadvantage is the need to replace older devices with newer devices that include this feature.

3M Two-Dimensional Bar Codes

This was the subject of a post on August 21st and was discussed by Chuck Bergman of Michigan DOT and Eric Hedman of 3M at the Innovation Council meeting. 3M has installed signs on I-75 in Michigan with two-dimensional bar codes embedded in their sign sheeting. A driver might see a sign saying ROAD WORK AHEAD but infrared cameras in the car would see a second embedded message telling the car to relinquish control to the driver, or to reduce speed automatically to 45 MPH, or any one of a number of other possibilities.

This approach will work well for longer term work zones and ones where the desired message is unlikely to change often. It will likely be low cost and could act as a fail-safe warning to autonomous vehicles. It does not update digital maps simply by installing the signs, but we assume that will be done manually at about the same time.

State DOT Work Zone Phone Apps

Many states require contractors to request lane closures in advance and then to report when those closures begin and end. Some now accomplish this through smart phone apps that make it quick and easy o report in real time.

This is already taking place but it does require someone to key in the closure when it begins and ends. And moving operations won’t be precisely geo-located. Still, it is inexpensive and requires very little effort.

Waze, HERE and other Crowd Sourced Traffic Apps

Users of these smart phone apps can note active work zones and other issues affecting traffic and that information is shared with all other users. This additional information is helpful but depends on users to remain current. Interestingly these apps are beginning to include data streams from work zone ITS systems. So the hybridization of these systems has already begun. And in our last post we noted that Caltrans traffic website known as QuickMap now includes Waze work zone data.

I2V (Infrastructure to Vehicle) Reporting via 4G/5G or DSRC

This was how we originally envisioned the process taking place. A radio of some sort might be installed in advance warning message signs or arrow boards where it would broadcast to approaching traffic to warn of upcoming work zones. These devices might also report slow or stopped traffic ahead. This may still happen, but advances in V2V (vehicle to vehicle) communications both 5G and DSRC make this less likely.

Automatic Reporting by Autonomous Vehicles

AV data collection will “see” and take note of variations of the real world roads from the digital map. This might include some standard deployment of devices in advance of work zones that could be recognized by algorithms to mean a work zone lies ahead.

This has not been suggested that we know of, but autonomous vehicles collect data continuously. That’s a lot of data. Machine learning and sophisticated algorithms will, in time, learn to recognize work zones. Logically those will then be reported automatically as work zones change. This may not occur for many years but it will happen automatically one day.

The change from driven to autonomous vehicles will be a very gradual one. Most experts believe it will take at least 25 years and even then older vehicles, collector cars, etc. will still be sharing the road with driverless ones. Furthermore, the choice of technology to warn of work zones will vary with location, construction activity, project duration, and more. As a result, differing combinations of technologies will likely be used in an effort to reach the greatest number of vehicles and to provide redundancy. After all, as time has proven over and over again, as cars become easier to drive, we become worse drivers. So it will be all the more important that we warn drivers and vehicles of work zones ahead.

Combining Queue Warning with Dynamic Late Merge

In our last post we talked about the ATSSA “Tuesday Topics” webinar held June 27th. Joe Jeffrey began the webinar with a discussion of work zone ITS basics. Chris Brookes of Michigan DOT shared some of his lessons learned. The final speaker that day was Ross Sheckler of iCone there to talk about coming trends in work zone ITS. Ross declared that the next big thing will be queue warning combined with dynamic late merge.

Mr. Sheckler began by looking at the state of our industry. He said that nationally there are nearly 1,000 deployments per year now. Costs of these systems are dramatically lower than they once were. And the economy and simplicity of these systems have not affected their flexibility. In fact, because applications vary, flexibility always has been and always will be an important feature of work zone ITS.

And for that reason it is very easy to add features, including dynamic late merge. As Ross pointed out, queue warning systems have their limitations. When volumes increase and queue lengths extend beyond the limits of a queue warning system additional steps should be taken. By instructing drivers to stay in their lanes and take turns at the merge point, it reduces the overall queue length, makes the best use of limited capacity, reduces road rage, and sometimes can even improve throughout.

In his drawings of typical system configurations he listed 4 sensors and 1 portable changeable message sign (PCMS) for queue warning. For queue warning with dynamic late merge he added a second PCMS at the merge point to tell drivers to take turns and a fifth sensor to narrow the gap between sensors midway through the affected area. So, in total, just 1 more sensor and 1 more sign. This is a minimal added cost and significantly increases the capabilities of the system.

The message here is that we can often solve multiple problems with one system. It just takes a slightly different logic in the controlling software. In this case you can solve problems with end of queue crashes and conflicts at the merge point with one inexpensive, easy to use system. So please remember this the next time you specify a work zone ITS system. Consider all of the challenges you face on that project, and think about ways work zone ITS may mitigate one, two or perhaps even many of them.

This webinar covered a lot of ground in a very short time.  It was recorded and can be viewed by ATSSA members anytime at: http://www.atssa.com/TuesdayTopics/Recorded. Or watch for possible future webinars on this same topic.