Looks simple, doesn’t it? In reality, presenting and forecasting accurate traffic data to I-35 commuters requires complex algorithms that integrate different data sources and constantly monitor the forecasted conditions for accuracy.

Traffic congestion is as familiar as bluebonnets on the roadside for anyone who’s traveled I-35 in the last twenty years. To meet capacity demands, the Texas Department of Transportation (TxDOT) is expanding I-35 in its Waco District (a 96-mile stretch from Hillsboro to Salado). At an estimated cost of $2.5 billion, the overall effort is made up of 17 smaller construction projects and targeted for completion in 2017.

The Texas A&M Transportation Institute (TTI) is providing TxDOT technical support on the project, namely in the form of a first-of-its-kind traveler-information system. The system integrates several methods for capturing data, forecasts congestion along the construction route, and provides that information to anyone who wants it.

The concept for the system is similar to modern traffic management systems used in urban areas. Put simply, it marries together three data-gathering methods to create reliable forecasts for travelers:

1. Bluetooth® technology — travelers’ devices (e.g., cell phones, laptops, and the GPS systems in newer cars) are anonymously pinged at point A and point B, giving a reliable estimate of travel time between the points.
2. Wavetronix sensors — placed strategically along the corridor at 17 points of high traffic interaction (e.g., where a state highway crosses I-35), the sensors capture traffic volume.
3. End-of-queue warning systems — relying on radar detectors mounted in orange barrels around work zones, speeds of approaching vehicles are measured as they near the work zone, and patterns of slowing traffic (indicating a backup in traffic flow) are noted.

Travelers will soon be able to access reliable forecasts via My35.org for what traffic on I-35 in Waco will be in an hour, before they ever leave Hillsboro, some 40 miles away.

“From our perspective, a real success story of this project is how we’ve interfaced with TxDOT’s LoneStar traffic management system,” says TTI Research Scientist Bob Brydia, principal investigator on the project. “Using their data protocols, we feed our information to them, and that helps drive the messages you see on the PCMSs.” PCMSs, or portable changeable message signs, display traffic forecasts along the roadway.

New portable changeable message signs like this one will soon keep I-35 travelers informed about forecasted construction delays along the corridor.

While congestion can be inconvenient for travelers, it can also be costly — in very real terms — for big business. Knowing where work zones are, what lanes will be closed, and when to expect slower travel is vital for companies like Wal-Mart and H-E-B. They rely on I-35 to get their goods via truck from major distribution hubs to their brick-and-mortar stores. When you’re talking perishables, traffic backups can mean the difference between fresh and spoiled milk — and that can translate into lost revenue for the company and higher prices for consumers.

Similarly, with better information on hand, EMS personnel can get to the scene of an accident sooner. The life-saving potential there really needs no further explanation.

Jodi Wheatley, Waco District’s information specialist for the project, acknowledges that without TTI’s help, the I-35 expansion effort would have been much tougher.

“Reconstructing almost 100 miles of interstate is a massive job for the department, and at the end of the day we at TxDOT want to be as responsive and helpful as we can to our fellow Texans,” Wheatley says. “Because of the scope of the project, that would be much more difficult without TTI’s logistical support and technical know-how. Maybe even impossible.”

Traffic congestion is as familiar as bluebonnets on the roadside for anyone who’s traveled I-35 in the last 20 years.

The interstate route — which in Texas stretches south from the Red River all the way to the Rio Grande at Laredo — has carried commerce and commuters across the Lone Star State for nearly 150 years. Before the modern highway was christened I-35 in 1959, much of it was known as the Chisholm Trail.

Once crowded with cattle in long drives north to Kansas, today’s I-35 has a similar reputation for being tightly packed — only now it’s bumpers, not bovines, causing the slowdown. In an innovative approach to improving the roadway’s capacity, the Texas Department of Transportation (TxDOT) created MY 35, a citizen-driven effort to expand a 96-mile stretch from Hillsboro to Salado of I-35 in the Waco District. At an estimated total cost of $2.5 billion, the overall effort is made up of 17 smaller construction projects and targeted for completion in 2017.

TxDOT Teams with TTI

Commuters and businesses alike will soon benefit from the expansion of I-35 in TxDOT’s Waco District. Due for completion in 2017, the project is widening corridor capacity and improving safety to better meet the traveling needs of Texans.

A project of this size is a huge undertaking, and not just when it comes to coordinating the construction itself. TxDOT is reconstructing nearly 100 miles of roadway in a relatively short amount of time, and that affects hundreds of thousands of citizens living nearby, tens of thousands of businesses, and millions of travelers over the life of the project.

TxDOT engaged the Texas A&M Transportation Institute (TTI) to provide independent technical support for the effort. One way TTI is helping is by providing mobility coordinators to keep citizen groups and businesses informed and lessen any negative impact of construction.

For example, TxDOT is converting many two-way access roads along the interstate to one way to improve safety. To business owners situated beside I-35, the change can seem threatening because, in the short term at least, it potentially changes customer access to their stores.

“Our job is to talk through the entire process with the business owner,” says TTI Research Engineer Jim Dale, lead mobility coordinator on the project. “We let them know we understand their concerns and help them see the longer-term benefits of the changes.”

Helping TxDOT get the word out is one of two major jobs for TTI on the project. The Institute developed a communications plan for the department and has done everything from designing flyers, truck stop signs and email alerts to organizing public meetings and writing, editing and distributing My 35 Central Texas News, a monthly newsletter aimed at keeping interested parties informed.

“Whatever means we use, our main goal is to get information into the hands of citizens and business owners so they can make the best decisions possible for their travel needs,” says Dale. “And very soon we’ll be getting the word out in a whole new way.”

Getting the Word Out in Real Time

http://my35.org

What Dale is referring to is a first-of-its-kind traveler-information system developed by TTI for the I-35 project. The system integrates several methods for capturing data, forecasts congestion along the construction route, and provides that information to everyone who wants it. The system, currently being refined, is a primary example of how TxDOT and TTI are working together to improve transportation in Texas.

“The purpose of the system is two-fold,” explains TTI Research Scientist Bob Brydia, principal investigator on the traveler-information project. “First, it’ll give reliable traffic forecasts for I-35 travelers while the expansion project is under construction. Second, after construction is finished, it’ll form the basis for a comprehensive traffic management system for TxDOT’s Waco District.”

The traveler-information system is similar in concept to modern traffic management systems used in urban areas. The unique aspect is combining construction data and corridor travel data for a long interstate highway passing through rural and urban areas. Put simply, the system marries three data-gathering methods together to create reliable forecasts for travelers:

1. Bluetooth® technology — Travelers’ devices (e.g., cell phones, laptops and the GPS systems in newer cars) are anonymously pinged at point A and point B, giving a reliable estimate of travel time between the points.
2. Wavetronix sensors — Placed strategically along the corridor at 17 points of high traffic interaction, such as where a state highway crosses I-35, these sensors capture traffic volume.
3. End-of-queue warning systems — Radar detectors mounted in orange barrels around work zones measure speeds of approaching vehicles as they near the work zone, and patterns of slowing traffic (indicating a backup in traffic flow) are noted.

TTI has developed computer algorithms to integrate this information together to create reliable traffic forecasts, which are then passed on to travelers. Once the system is fully up and running, travelers will be able to access reliable forecasts via the Internet of what traffic on I-35 in Waco will be in an hour, before they ever leave Hillsboro, some 40 miles away.

It sounds simple enough in theory, but gathering and analyzing the data and creating reliable forecasts are incredibly complex tasks. And different information systems have to talk effectively with one another to make sure the information stays accurate and useful by the time it reaches travelers.

“From our perspective, a real success story of this project is how effectively we’ve been able to interface with TxDOT’s LoneStar traffic management system,” says Brydia. “Using their data protocols, we feed our information to them, and that helps drive the messages you see on the portable changeable message signs [PCMSs].” PCMSs display traffic forecasts along the roadway.

While congestion can be inconvenient for travelers, it can also be costly — in very real terms — for big business. Knowing where work zones are, what lanes will be closed, and when to expect slower travel is vital for companies like Walmart and H-E-B. They rely on I-35 to get their goods via truck from major distribution hubs to their brick-and-mortar stores. When you’re talking perishables, traffic backups can mean the difference between fresh and spoiled milk — and that can translate into lost revenue for the company and higher prices for consumers.

Similarly, with better information on hand, emergency management services personnel can get to the scene of an accident sooner. The life-saving potential there really needs no further explanation.

“Right now, the main way for alerting travelers is via PCMSs and daily email alerts,” explains Brydia. “Very soon we hope to take advantage of social media, including Twitter, and supply real-time information to TxDOT’s My35.org website in the form of a dynamic traffic map.”

Jodi Wheatley, Waco District’s information specialist for the project, acknowledges that without TTI’s help, the I-35 expansion effort would have been much tougher.

“Reconstructing almost 100 miles of interstate is a massive job for the department, and at the end of the day we at TxDOT want to be as responsive and helpful as we can to our fellow Texans,” Wheatley says. “Because of the scope of the project, that would be much more difficult without TTI’s logistical support and technical know-how. Maybe even impossible.”

This Issue

Partners in Transportation Research

Volume 48, Number 3
September 2012
Issue Overview

On this page:

• TxDOT Teams with TTI
• Getting the Word Out in Real Time
• For More Information

“Reconstructing almost 100 miles of interstate is a massive job for the department, and at the end of the day we at TxDOT want to be as responsive and helpful as we can to our fellow Texans. Because of the scope of the project, that would be much more difficult without TTI’s logistical support and technical know-how. Maybe even impossible.”
Jodi Wheatley, TxDOT Waco District information specialist

For more information:

Bob Brydia
(979) 845-8140
r-brydia@tamu.edu

]]> http://tti.tamu.edu/2012/09/01/the-i35-expansion-project/feed/ 0 http://tti.tamu.edu/2010/03/01/now-taking-it-to-the-streets-collecting-travel-time-data-speed-with-bluetooth-technology/ http://tti.tamu.edu/2010/03/01/now-taking-it-to-the-streets-collecting-travel-time-data-speed-with-bluetooth-technology/#comments Mon, 01 Mar 2010 18:36:29 +0000 Chris Sasser http://tti.tamu.edu/?p=1494

A screen shot of the Houston TranStar website.

You might be familiar with the name Bluetooth® as a way of wirelessly talking on your cell phone. More generally, it’s a personal area network that connects devices wirelessly over short distances.

Researchers at the Texas Transportation Institute (TTI) are using Bluetooth technology for a host of applications involving traveler information, traffic management and planning systems. Currently these data are collected using toll tags, GPS, license plate recognition and cellular phone networks, which can be expensive and inefficient. Data collection by Bluetooth presents a viable alternative.

How the Technology Works

Each Bluetooth device has a unique identifier called a Media Access Control (MAC) address, which the device transmits within a short range.

“A motorist with a Bluetooth-enabled device drives by a road sensor, and the sensor reads the MAC address,” says Darryl Puckett, a TTI research scientist investigating uses of Bluetooth technology. “Further down the road, another sensor reads the MAC address again, and the system matches it to the first reading.” Software then determines how long it took to travel from one reader to the other and calculates the average speed.

Privacy is an important concern. MAC addresses are not directly associated with a specific user and do not contain any personal information. Users can also disable the Bluetooth function of their device to prevent it from being read.

The benefits of this anonymous wireless address matching (AWAM) system are many. A large percentage of the population has Bluetooth devices, so the technology is easy and nonintrusive for motorists. The roadside readers are low cost and low maintenance, using standards-based, non-proprietary equipment and protocols.

Applying the Technology

Funding from the University Transportation Center for Mobility (UTCM) assisted TTI researchers in developing a full, end-to-end solution for AWAM, with the following features:

• roadside hardware and software for reading and forwarding MAC addresses,
• host software for calculating real-time and historical travel time and speed data, and
• analysis and graphics capability to view current and historical data graphically.

Border Crossings

The ability to accurately estimate wait times at international border crossings is one of the goals of Bluetooth technology applications.

Millions of motorists cross the U.S.-Mexico border every day, often with long delays. Current methods of determining delay — usually by visual estimates or motorist survey — are unreliable.

“Deployment of Bluetooth technology at the border is geared toward obtaining crossing times of passenger vehicles, which can then be used to accurately estimate wait times,” says Rajat Rajbhandari, TTI associate research engineer. “This project was the first of its kind to use Bluetooth technology to gather traffic information in Texas.”

Researchers collected data at three ports of entry in the El Paso, Texas, region: the Bridge of the Americas, Ysleta and Paso Del Norte. The study confirmed that Bluetooth technology could be used to measure U.S.-Mexico border crossing times. A follow-up project will deploy Bluetooth sensors at the Ysleta port of entry in El Paso and compute the crossing time in near real time.

“We’re also working on deployment of RFID [radio frequency identification] technology at border crossings in El Paso, Laredo, Pharr and Arizona to get crossing times of commercial vehicles,” says Rajbhandari. “Crossing time information for both passenger and commercial vehicles is crucial to understand the operational and planning aspects of international border crossings.”

Urban Areas

Travel time data can help commuters choose when and what route to travel and help planners identify congested segments for operational or infrastructure improvements. TTI has worked on several projects in Texas:

• Houston commuters can check the TransStar website to see how long it will take to get to work. The partnership between Houston TranStar and TTI is investigating whether AWAM can expand this coverage to arterials.
• AWAM proof-of-concept demonstrations with the City of Houston, the Texas Department of Transportation (TxDOT) and Harris County on urban arterials showed that Bluetooth device penetration is sufficient to collect high-quality travel time data.
• In a project for TxDOT, TTI collected travel times and speeds on identical roadway segments using a toll tag reader system and the AWAM system, with comparable results.
• TTI has deployed the AWAM system at several west Houston intersections to monitor travel time for a network of urban arterials.
• TTI demonstrated the AWAM system on parallel routes to U.S. 75 North Central Expressway between Dallas and Richardson.

“I see this technology as an exciting, innovative way to obtain traffic information in places where we would not otherwise be able to gather data because of the cost,” says David Fink, a TxDOT transportation operations engineer with Houston TranStar. “Other technologies can be up to eight times more expensive than using Bluetooth technology. In some cases this is just cost-prohibitive.”

The anonymous wireless address matching (AWAM) concept for travel time data collection.

This Issue

Improving Our Transportation Operations

Volume 46, Number 1
March 2010
Issue Overview