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.