Freightliner LLC said it has completed a significant three-year study with the U.S. Department of Transportation (DOT) – a field-operational test of Electronically Controlled Braking Systems (ECBS) and other safety technologies.

The study's results will be used to improve truck safety systems' performance, reliability, durability and maintainability.
"With the massive amount of data we collected and provided to the DOT, they'll be equipped to draw conclusions about stability and braking systems that may reduce rear end, lane change and merge collisions, lane departure, rollover and understeer and oversteer instability – ultimately saving lives," said Scott Smith, executive engineer for Freightliner LLC.
The study tested the compatibility of combinations of tractors and trailers equipped with ABS, ECBS, disc and drum brakes, and enabled safety technologies. These technologies included adaptive cruise control (ACC), Yaw Stability Control, Roll Stability Control, and air disc brakes.
In 2003, the DOT awarded the cooperative research project to Freightliner LLC and its team, which included Wal-Mart, Battelle, Bendix Commercial Vehicle Systems LLC, Meritor WABCO and the U.S. Army Aberdeen Test Center.
Freightliner LLC collaborated with Wal-Mart to dedicate a test fleet of 48 new Freightliner Columbia tractors with 58-inch SleeperCabs to the project. The trucks were equipped with on-board computers, ECBS and ABS. Similarly, Wal-Mart agreed to outfit 100 new Great Dane trailers with the technology required of the field test. The fleet was then operated out of Wal-Mart's distribution center in Loveland, Colo., to collect vehicle onboard system data, maintenance data and driver experience data.
The Freightliner tractors were separated into two groups. The first group consisted of 40 tractors and 60 trailers that were used to determine the compatibility and performance of unmatched combinations of tractors and trailers equipped with ECBS or ABS.
The second group of eight tractors was used to measure ECBS and ECBS-enabled safety technologies on matched tractor-trailers with brake control systems from the same manufacturer.
Making one or more 300-mile round-trips a day, each Freightliner truck distributed perishable and dry goods between Wal-Mart hubs, distribution centers and outlying stores.
Data was recorded over an initial six-month period from May to October 2005 with enabled technologies in the vehicles turned off. During the second six-month period from November 2005 to April 2006, the technologies were fully functional and interactive.
"Conducting this comparative test over a 12 month period allowed us to look closely at the vehicles' complex configurations," said Smith. "We were able to gather substantial data by operating the vehicles in a real-world operating environment – as opposed to a simulated test – and supply the DOT with critical safety data for evaluation."
DOT is still analyzing the results of the test.