Using GPS to Track Pole Truck Turning Movements Presented by: John Wolf, PE Senior Designer ODOT, Region 1 Preliminary Design & Ron Singh, PLS Chief of Surveys/Geometronics Manager ODOT, Technical Services

The Problem Intersection at Bennett Road & US 30 High volume, multilane highway 3 Crashes in 2008 involving passenger cars and log trucks 2 injuries and 1 fatality resulted Permitting issue regarding overhang on long loads Maximum Overhang was dependant on wheelbase and trailer type Overhang was measured from rear axle Pole trucks need access to pole yard

Bennett Road Conflict Point

Bennett Road

Accidents at Bennett Road

Accidents at Bennett Road

The Challenges Timing was critical Motor Carrier issued a pilot car requirement on log trucks with large overhang, effective 9/12/08, for over 260 permit holders Variable vehicle configurations (What should be analyzed?) Pivoting trailer bunks influence log sweep path Turning movement software limitations? The need to applying the turning movements to multiple situations Multiple intersection configurations Freeway ramp terminals Multilane Roads

Unique Elements of A Pole Truck Long Wheelbase Large Overhang Rear Bunk/Pivot Point Front Bunk/Pivot Point Adjustable Stinger Hitch and Compensator

Extendable Stinger 12’6” Total Length 5’6” Available Adjustment Compensator Vehicle #2

12’ 13’

AutoTURN v5.1 AutoTURN is a CAD-based program that simulates low speed turning maneuvers for highway vehicles Vehicle inputs Default vehicle configurations User defined vehicle configurations Inputs include number of axles, axle spacing, tractor/trailer length, and distance to pintle hitch Limitations AutoTURN v5.1 does not account for adjustable length “stinger” pintle hitch Turning accuracy for this type of tractor/trailer uncertain

AutoTURN Inputs Default truck templates Modified pole truck templates Critical measurements include bumper, axle spacing, hitch location, axle location, bunk location, overhang, front of load Modified pole truck templates

AutoTURN Outputs

Course of Action Collected data from ODOT Motor Carrier on common pole truck configurations Research other turning simulator software ODOT Maintenance staff coordinated field testing of two pole trucks using GPS tracking data Note: ODOT Motor Carrier Division also collected data on accident history of pole trucks on Oregon highways and neighboring states log truck permitting requirements Investigated older versions of AutoTURN as well as a log truck turning software developed by the forestry service.

OREGON STATE FAIRGROUNDS – TEST SITE

The Survey Approach

Truck Turning Sequence

GPS Devices 12’ Between Cones 5’ 5’ 5’ 5’ 5’ Ribbons Spaced at 5’ Intervals From Rear Bunk Test Vehicle #2 12’ Between Cones Cones Offset 2’ from Path for Driver’s Side Front Tire

After Data Collection Create vehicle configurations to replicate field test Run AutoTURN analysis Compare results Run sensitivity analysis of sweep path based on overhang length Report Results to Motor Carrier and the Trucking Industry

No Scale

RAW GPS DATA COLLECTED

Comparison of Field Tests to AutoTURN – Vehicle #1

Comparison of Field Tests to AutoTURN – Vehicle #2

General Findings of Field Test and Analysis Sweep path is dependent on vehicle configuration and length of overhang from the rear bunk Sweep path is the same for both left and right turns AutoTURN v 5.1 reasonably predicts pole truck turning movements for various conditions Path generated using AutoTURN v 5.1 predicted log sweep within 2’ for Vehicle #1 and 1’ for Vehicle #2 compared to GPS AutoTURN's maximum error in the trailer off tracking was between ½’ and 2’ (2’ occurred as the vehicle exits the curve) Multiple curves compound the error in the AutoTURN software

Outcomes ODOT Motor Carrier changed permitting requirements for overhang, effective 11/24/2008 Length of overhang was limited to 1/3 Wheelbase with a 25’ maximum for multilane roads Changed the point which overhang is measured from Lifted the temporary pilot car restriction for vehicles meeting these requirements Requirements are posted at: http://egov.oregon.gov/ODOT/MCT/ Currently investigating an intersection improvement project at US 30 and Bennett Road to better accommodate pole trucks

Questions?