1. Tykey Truett Center for Transportation Analysis Oak Ridge National Laboratory (865)574-4225 or LFT@ornl.gov ROLLOVER WARNING!! Truck Roll Stability Data Collection and Analysis

2. Objectives Collect and analyze vehicle and highway data relevant to the problem of truck rollover crashes Evaluate the performance of the equipment used to collect the data

3. Project Partners FHWA/FMCSA Oak Ridge National Laboratory U.S. Xpress Enterprises Praxair Volvo Trucks of North America Wabash National Corporation Control by Light (formerly of Raytheon) Tennessee DOT

5. Types of Data Collected GPS Data Speed RPM Odometer Strain (weight transfer) Ambient Air Temp Weight on Rear Axle Lateral Acceleration Longitudinal Acceleration

6. Data Management and Analysis In trucks, logged to a file and saved to a memory card Transferred to ORNL server via FTP Validated and saved to databases Characterized using a statistical tool and spreadsheet Mapped using a GIS tool Overlaid on satellite photo images

7. Synopsis of Data Files Ten files received between 6/6/00 and 1/25/01 Files ranged from 499 kB to 160,407 kB Some had trailer readings; others did not Some had date in file; others did not Early data files were collected prior to May 1, 2000

15. Summary Using trucks in revenue service, data were collected from both trucks and trailers Both box trailers and tankers were used The equipment used for data collection on the vehicle was evaluated The data were analyzed for accuracy, timeliness, and applicability for a truck warning system

16. Equipment Evaluation Trailer-to-tractor communication was a problem and led to missing trailer data Connectors on the on-board computer and attached devices caused intermittent data logging Lack of proper shut-down procedures on the tractor PC eventually caused operating system failure

17. Data Accuracy and Timeliness GPS data can provide very accurate real- time vehicle position Analysis of limited data sets indicate: –Instrument drift and temperature can be estimated –Measured lateral acceleration and weight transfer are reasonable and correlated –Trailer data can be used to indicate roll stability –“Bad curve” database can be generated

18. Conclusions Data collected by the tractor and trailer can be used effectively to provide a dependable, reliable, and timely rollover warning system for truck drivers Such a warning system would not require expensive roadside beacons