Sending Work Zone Warnings to Cell Phones

workzone-alertThe Minnesota Department of Transportation just released a study looking at one way of triggering in-vehicle messages in vehicles approaching work zones. The authors Chen-Fu Liao and Max Donath of the University of Minnesota tested the concept of sending low-energy BlueTooth messages to Android phones equipped with a custom app they call Workzone Alert.

The app triggers an audible, visible and/or tactile warning to the driver as he or she approaches a work zone. Drivers who are speeding can also be warned to slow down. And the app can even disable calling and texting while within the confines of the work zone.

Report 2016-38 entitled “Investigating the Effectiveness of Using BlueTooth Low-Energy Technology to Trigger In-Vehicle Messages in Work Zones” was published by the Minnesota DOT. You can download a copy HERE.


Their design worked well and proved that vehicles traveling at speeds of up to 70 MPH could receive warning messages as they approached a work zone.

We have talked about a future with DSRC “pods” transmitting to vehicles. We have also talked about those same DSRC devices attached to PCMS as a stop gap to reach all vehicles until nearly all are equipped with receivers. But a better way might be through 5G cell service as that is already available and in most vehicles.

These “BLE tags” use very little power so they could be attached to message signs or arrow boards without affecting the signs performance. When packaged with a small battery they could also be attached to a simple sign post or overpass.

The downside is the cell phones must currently be placed into a BlueTooth discover mode to find existing tags. This uses more power and results in reductions in charge life for the phones. But if this technology continues to show promise, the Android and iPhone operating systems could surely be changed to receive these messages in something similar to a discover mode but one that uses far less power when not receiving. The BLE tag locations are stored allowing phones to run Workzone Alert in background except when passing known tag locations.

They also attempted to make the technology easy to deploy. A second app was developed to make it easy for traffic control contractors to update the message that Workzone Alert displays for a specific BLE tag.

Work at the U of M continues. The current, second phase of research is looking at human-factors considerations for alerts. What wording and format should be used to get the best results? In the third phase they will look at how best to maintain the BLE tag database, who should be able to make changes, and if it is practical to tie this into 511, Waze or Google Maps. Stay tuned as this promises to develop quickly!

Enterprise to Evaluate Use of Arrow Boards for Real-Time Traffic Updates

enterpriseThe American Traffic Safety Services Association (ATSSA) just concluded their annual Traffic Expo held this year in Phoenix, Arizona. Their Innovation Council met on Saturday, February 11th. The meeting was “standing room only” and included several great presentations. One of them was by Dean Deeter, President of Athey Creek Consultants on a project they are leading for Enterprise. You may remember that Enterprise is a consortium of 14 states conducting pooled-fund studies to jump start promising new technologies. They like to do more than just study a problem or technology. Instead, their goal is often to develop an operational concept and system requirements for a promising new idea.

In this project they hope to develop an automated system to update traveler information systems with work zone conditions as they change. Their concept begins with an arrow board. But the arrow board would be equipped with a unit that is GPS enabled. When the arrow board is turned on, it would notify the traffic management center (TMC) over a digital wireless link. It would also tell the TMC what mode it is flashing (right arrow, left arrow, or caution mode). With that information the system will know when a lane closure begins, and which shoulder, lane or lanes are being closed. When the arrow board is turned off, it would notify the TMC that the closure has been removed.

In this way the system will provide specific, real-time information about each work zone. We aren’t doing that very often now. Instead, most work zone warnings are generic. Our portable message signs just say there is road work ahead and either to expect delays or use caution. That’s not as helpful as it could be.

Furthermore, travel websites like Google Maps only tell you there is a work zone. It may tell you when the lane closure is planned to begin and end. But that’s about it. Users cannot normally tell if that work zone will delay them enough to justify taking an alternate route.

The Enterprise study will develop this concept in phase one. In phase two it will work with one or more member agencies to integrate such a system into their ATMS, control permanent message signs, and more. Work Zone ITS Blog will continue to follow this and report developments as they are made available.

It is interesting that they have chosen to integrate directly with state ATMS systems. Many states’ IT security prohibit outside data sources. Only data collected from DOT sensors is used. That’s fine for permanent ITS but it is a real problem for the portable elements found in work zone ITS systems. States that operate within a closed network can never take full advantage of work zone data. So we hope they succeed. But only time will tell if they do, or if, instead, work zone data finds it’s way directly to end users through phone apps like Waze.

Medical Wearable’s and Autonomous Vehicles (and Work Zone ITS)

screenshot-www-linkedin-com-2017-01-10-10-12-32Marty Weed, who recently retired from WsDOT, is a good friend and still very much involved in work zone ITS. He ran across a talk on LinkedIn comparing medical wearable technology with autonomous vehicle technology. In the video Randy Hamlin, a VP and engineer at Phillips, said that both technologies are further ahead than policy or behavior. The technology won’t slow down adoption. Instead it will be policies or behaviors. I believe we can add Work Zone ITS to this comparison as well.

You can view his presentation HERE.

Mr. Hamlin stated that both industries have the opportunity to meet a very large and growing need. For medical wearable’s it is the opportunity to reduce chronic disease. For the autonomous vehicle industry it is the opportunity to reduce the chronic roadway fatalities of 30,000+ per year. But before either industry can make an impact, each must first achieve three key factors:

  1. Access
  2. Integration
  3. Adoption

Under access he said that for a technology to achieve widespread adoption it must be accessible. One easy way to make that happen today is to take advantage of the personal cell phone market. These devices have become very powerful, very inexpensive, and everyone owns one. So instead of expensive, stand alone systems, create hardware that interfaces with your phone using an app. This is already taking place in all three industries.

His second factor, integration, revolves around data. Medical wearable’s generate a great deal of data. So do autonomous vehicles. And so do work zone ITS systems. The data quickly overwhelms the practitioners. They quickly begin to ignore it and go back to doing what they did before. Because they just don’t know where to start in making use of that data. As he pointed out, data must be relevant.

Autonomous vehicle manufacturers are addressing this by keeping most of the data to themselves. They use it for product improvement and verification. They only release data to other users that is relevant. Data packages are customized for each group of users. This requires a good understanding of each user’s needs and habits, but results in faster and broader adoption.

Work zone ITS can learn from this. We must understand what our customers need from data. Traffic operations will want one package. Construction may want something else. And systems operations folks may want yet another set.

This will vary from state to state and even from one district office to another. A more urban district may watch volumes while a more rural district may be more interested in speeds or queue lengths.

As Mr. Hamlin said, for our systems to impact roadway work zone fatalities we must first achieve access and then integration. Only by packaging our data so that it is relevant can we hope to achieve the third factor, adoption. Once users become accustomed to receiving timely and useful data, they will come to depend on it. And once they depend on it, our systems will see far more common use.

Improving the Effectiveness of Smart Work Zone Technologies, Part 2

illinoisstudyIn our last post we discussed a brilliant new paper published in November by the Illinois Center for Transportation Studies. Today let’s look at their conclusions regarding work zone travel time systems. The writers point out that, “Two critical components for the success of a smart work zone deployment are the quality of the traffic data collected by sensor networks and the algorithms used for data processing.” We examined sensor types last time. Today we look at algorithms.

They conclude that, “The travel time estimation is consistently poor for all algorithms and sensor networks investigated in this study. The main reason is that the instantaneous travel time calculation is a poor estimator of the true travel time in a dynamic traffic environment. In addition, the use of Bluetooth sensors can only provide the travel time of vehicles that just exited the work zone. Consequently, the travel time estimation even using Bluetooth sensors is not likely to improve the accuracy of the travel time estimates when the traffic conditions are quickly changing.”

This makes perfect sense. In a work zone you are more likely to see frequent and dynamic queuing. And that is the kryptonite for every algorithm superman. It’s too bad, because we would all like to see accurate travel time estimates, especially for work zones with significant impacts. But, ironically, it is those impacts that make estimation so difficult.

They also discussed the potential use of more advanced algorithms. This is a subject for which I have only a very limited understanding. So I am not able to examine the relative advantages and disadvantages of popular methods. But for work zones, they really aren’t practical anyway. Unless it is a very long term project, one lasting several years, the work required ahead of time to test and adjust the algorithms is expensive and still won’t make much of a difference in the travel time accuracy.

As an industry, we have worked for years to make our systems faster and easier to set up. This, to my mind, would be moving backwards. Instead, let’s work to make our travel time estimates more useful to travelers. Perhaps it makes more sense to talk about delay times. Drivers seem to expect predicted travel times to match their experience perfectly. But when it comes to delay times, they are more likely to be relieved when the delay they encounter is slightly less than predicted.

Work Zone ITS and Data Sharing Services

wazeOn January 2nd iCone announced a new data-sharing partnership with Waze.  Waze, as you may know, collects travel time data from its users and then shares it with them. Users may also note special problems like work zones or crashes as they travel. They even note the prices at individual gas stations.

Waze already shows the work zones reported by state DOTs. But now any work zone equipped with iCones will also show up. After all, not all work zones are reported. And not all that are reported actually take place. Better yet, they will appear as soon as the work begins, and they will disappear as soon as the work ends, making this truly real-time!

This is important for one simple reason. As work zone data is generated by our systems, it quickly overwhelms the DOTs. Most systems offer a live feed to the DOT but only a very few DOTs have incorporated that data into their DOT travel time systems. Portable work zone system data stands alone and apart from permanent systems. So it is not reaching Waze or Inrix or any travel time system. And that means it is not reaching the end user.

This new partnership skips the intermediate step and supplies the data directly to Waze. Users will begin seeing the benefits right away, rather than years from now. Drivers will become more aware of work zones and many will bypass them altogether. In both cases work zones become safer, and our roads more efficient.

Read the press release HERE.

Learn more about Waze or download the app HERE.

The Work Zone ITS Blog – Post #100

canstockphoto4235293This is post number 100 for the Work Zone ITS Blog. So I hope you will humor us as we celebrate this milestone and look back on the past few years in our industry. The blog began in August of 2012. The goal was to initiate a conversation on work zone ITS. We imagined lots of public comments and a lively discussion on topics of interest. That has not been the case. Too many of you are shy or prefer to keep your opinions at the unofficial level. And that’s OK.

It has been well worth doing anyway. We get lots of comments, but they are back channel rather than public. Many of those have led to additional posts. So thank you all for that help.

Our industry has changed significantly over these past four years. Acceptance of work zone ITS is greater than ever before. We have gone from a deployment here and there to required use in states like Texas. Other states like Illinois and Indiana are now using systems on most major projects. Many more states are ramping up their use of these systems, as well.

Manufacturers have come and gone. Some that are still here have changed their business models. Most manufacturers now understand that a local presence is important to provide agencies with fast, frequent service of their systems. So those manufacturers are building relationships with local contractors.

The technology has proven itself. LEDs, batteries, solar systems, and digital communications have all greatly improved. In particular, 4G modems and the cost and availability of satellite communications have made great improvements. Those improvements have resulted in systems that are easy to deploy and super-dependable while reducing costs at the same time.

Our systems will continue to evolve, adding more features and seamlessly integrating with other systems and devices. Work zone ITS is already very cost-effective. Pricing may continue somewhat lower, but most cost reductions will come at the contractor level as they amortize their fleets and learn what their true costs of deployment are.

New challenges lie ahead, especially with regard to automated and autonomous vehicles. There is a lot of talk about our place in that new world. And as that becomes clearer, it will be interesting adapting our systems to help guide driverless vehicles through our work zones safely and efficiently.

Finally, as we start 2017, I would like to thank those of you who have been here since the beginning. You know who you are. About 25 of us have been in this more or less from the start. That group includes manufacturers, contractors like Road-Tech, and some state DOTs. You are the true believers and it is because of your vision and hard work over these many years that have made this all possible. We have a bright future ahead of us and we look forward to working with you all.

Improving the Effectiveness of Smart Work Zone Technologies, Part 1

illinoisstudyA brilliant study was published in November by the Illinois Center for Transportation Studies entitled “Improving the Effectiveness of Smart Work Zone Technologies.” The principal researchers were Yanning Li, Juan Carlos Martinez Mori and Daniel Work. Download it here.

It is brilliant for a couple of reasons. It moves past the studies we conduct over and over again that look at the effectiveness of smart work zone systems. Those have been done, and there really isn’t much more to be learned from additional studies. We know they work. It has been proven. Enough said.

Instead, this study looks at ways of making something good, even better. There is so much new information is this study that we will discuss it in two separate blog posts. This first one will look at their conclusions regarding sensor types, sensor spacing, and missing data. The second will consider travel time estimation and, in particular, their recommendation of the Kalmar filter algorithm.

Let’s begin with sensor types. The study focuses primarily on doplar and side-fire (RTMS) sensors.  They compared the advantages and disadvantages of each and concluded that for most work zones systems there is no advantage to RTMS type sensors. The RTMS provide more accurate flow measurements than radar due to fewer occlusion issues. But they do cost more and are more difficult and time-consuming to set-up and configure. They wrote the, “analysis indicates the types of sensors do not have significant influence of the performance of existing smart work zone systems. It is suggested the choice of sensor types should depend on the specific requirements and constraints in each work zone.”

They went on to say that given the extra cost of RTMS, you are normally better off spending that money on additional doplar sensors, as more sensors improve the data quality far more than the sensor type. Of course, if lane by lane counts and classifications are needed to meet the deployment goals, RTMS is the only practical solution.

Next they discussed sensor spacing. Most of us in the work zone ITS industry suggest sensor spacing of between 1 mile and one-half mile apart. This study confirms what we learned through experience. They said the closer you place your sensors to each other, the better the data quality. “When more sensors are deployed, the systems provide faster notification of changes of the traffic conditions and increase the estimation accuracy of the traffic conditions.”

However, anything closer than a half mile apart provides negligible additional benefits. “When the sensor spacing is smaller than 0.5 mile, the benefit of additional sensors … is marginal.”

A third topic they covered was missing data records. This has not been covered in any detailed way in previous studies. But it is important. They studied only two projects but for those projects found they were missing as much as 10% of the data records. They did point out that the system messages continued to be sent to the message signs. But what if the interruption was sufficient to delay those messages?

One vendor suggested the data records were missed due to the cellular carrier dropping them in favor of voice transmissions. If true, this underlines the need for redundant communications. Satellite backup or better cell service is a must. If data is dropped for more than a few seconds it could affect the timeliness of warnings to traffic upstream. And if that data will also be used for work zone performance measurement, it causes additional problems. A measure of system data transmission performance should be included in the evaluation of every work zone ITS deployment.

So, in short, simple systems with more sensors are better than more complicated ones.

Spacing of a half to one mile is best. Anything greater quickly loses accuracy and anything less is not cost-effective.

And agencies should require a data transmission reliability report to be sure that most of it is getting through, even during major incidents.

In a future post we will return to this study to examine algorithms, especially for travel time systems. In the meantime, download this important study!