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!

Pooled Fund Studies and New Product Development

I recently participated in an Enterprise pooled fund study to develop an Intersection Conflict Warning System (ICWS). We will talk more at some future date about the system. But today I would like to talk about the process. I am a businessman. I have always been a little uncomfortable with government designing product. In my experience market forces will always do a better job of design and refinement than a committee could possibly do.

But in this case someone needs to dictate how the system should work. In terms of technology, this is a simple system. But sign placement, when it should display warning messages and for how long, the effects of turning movements on those design parameters, fail safe modes, and many other performance specifications cannot be left to each manufacturer to decide separately.

The agency may be found liable if the system does not do those things correctly. It is in their interest to clarify their expectations up front. There are also several of these systems in use already in states like North Carolina, Iowa and Missouri. To maximize their effectiveness and to prevent confusion, the appearance of the equipment and the way it works must be consistent from state to state. So for both of these reasons it made good sense to decide those questions now.

The group began last year with a series of conference calls. The first ones resulted in a high level list of needs and wants for such a system. Then general functionality was described to support those needs. Finally, the group began to set actual parameters for the system performance. Things like on time and off time for the different signs, distance in advance of the intersection where signs should be placed and where vehicles should be detected. These discussions were difficult over the phone so they decided to hold a face to face meeting to hash them out.

A total of nine people were at that final meeting. One county DOT and four state DOTs were represented including a current member of the National Committee on Uniform Traffic Control Devices. Two of us from the American Traffic Safety Services Association (ATSSA) were there to represent industry, one from the sign industry and another (myself) from the rural ITS industry.

The group was led by Ginny Crowson of Athey Creek Consultants. She did a wonderful job of keeping us focused and on track. The group was championed from the beginning by Jon Jackels of Minnesota DOT. Unlike many agency folks, he pushed for industry involvement. He didn’t want to get months down the road with this process only to find out that industry either could not or would not manufacture the system.  He knew it would take a little longer with everyone participating, but he also knew the results would be far more developed and ready for market.

Everyone there was passionate about highway safety and the use of technology to improve it. There were disagreements but they were always held to the same standard: which idea will result in better, more cost-effective performance. I believe the size of the group was just right, too. Everyone could be heard and a trust developed quickly between the group members.

The meeting ran from noon the first day to noon the second day including another two hours during and after dinner. We didn’t get everything done, but we came very close. The most difficult and time consuming issues were all covered thoroughly resulting in a consensus on each one.

This is a process I would recommend any time a new product or service would benefit by starting with the performance requirements. We did not discuss how companies should design their systems to meet these parameters. The choice of technologies will be left up to each manufacturer. We were only concerned with what it had to do and whether it was feasible and cost-effective.

Intersection Conflict Warning Systems

Last month we talked about work zone ITS. This month, in the interest of equal time, we will delve into rural ITS. Minnesota DOT and the Enterprise Pooled Fund Study have been leading a nationwide effort to advance and promote intersection warning technologies. I am excited about this for a number of reasons not least of which is that it uses technology in areas where they have not been used before. We are accustomed to seeing ITS deployments on freeways and major arterials in and near cities. But uncontrolled intersections on two lane roads have not benefited – until now.

These systems have been used since 1998 to warn drivers at stop signs that cross traffic is approaching and that it will not stop. System architecture has evolved and  varies still but most include sensors to detect approaching traffic on the main line.  The approach speed is detected and analyzed to see if it is a danger to cross traffic. If so, some form of blank out sign is turned on to warn cross traffic.  These are simple, usually solar powered, and cost as little as $30,000 per intersection.

We have all enjoyed success driving down the number of fatalities and serous injuries on our roads. But there is still much work to be done on rural roads. They account for more than half of all fatalities yet only 30% of the vehicle miles driven. A major portion of those fatalities occur at rural intersections. Drivers stop and then pull right into the path of oncoming vehicles. Usually this is due to line of sight or gap acceptance issues. For whatever reason they fail to truly “see” the oncoming traffic.

Early study results have shown excellent results from intersection warning systems.

There are some ongoing discussions:

  • What should the warning signs look like? Some guidance is available and presentations have been made to the National Committee seeking further direction.
  • What are the legal implications? This is a supplemental device. There is still a stop sign at which drivers must stop and look both ways before proceeding. So the thinking is that even if the warning system failed to warn, the driver is still responsible. Many systems include multiple redundant sensors and a log of traffic detected, speeds, and warning triggers with date and time stamp.
  • These can’t be placed everywhere, so where should they be used? Clearly intersections with high concentrations of crashes should be the first ones. But after that?

Another advantage of these simple systems is their portability. If you have an intersection with frequent crashes and you plan to realign it, or add signals, or some other mitigation when funding becomes available, this is a low cost way of “fixing” the problem until you can afford to do more. Afterwards, you can move the system to another intersection.

What can we, as an industry, do to promote these systems? What questions do you have about system architecture? Are there any issues I haven’t mentioned? Let us know what you think!