Large trucks with blind spot warning systems have approximately 50 percent fewer safety-critical events.

Promising technologies for commercial motor vehicles (CMVs) in North Carolina.

January 2014
Kernersville,North Carolina,United States

Summary Information

This study evaluated the effectiveness of blind spot warning (BSW) systems to improve commercial motor vehicle safety. Twenty (20) commercial motor vehicles (CMVs) equipped with BSW systems were evaluated over an 11 month period during normal revenue-producing operations in North Carolina. The BSW system used infrared technology and an array of lasers to create a 3-D detection zone on the driver and passenger sides of the vehicle. LEDs mounted on side-view mirrors were used to alert drivers of objects or vehicles in blind spots.

To evaluate performance, a data acquisition system (DAS) with sensors and video cameras was installed on each truck to track vehicle location using GPS, calculate vehicle lane position using machine vision, measure steering and throttle movements using a gyro and accelerometer, and collected performance data using an in-vehicle network.

The BSW system was initially tested on a test track along side other vehicles to establish parameters for system functions and false alarms. Once system functions achieved acceptable performance the system was installed on a fleet of CMVs to support further field testing.


Evaluation data were collected before and after system features were activated on each truck. Potential safety benefits were determined based on operator driving behavior as measured by the rate of involvement in safety-critical events and changes to lane change/merge behavior after the BSW system was introduced. Sample data were collected each week to analyze impacts when the system was used. A total of approximately 722,639 miles of on-road data were collected. Questionnaires were also distributed to participants before and after the system was activated in each truck to assess driver expectations and opinions on system performance.

A total of 99 safety-critical events were identified during the baseline condition which included 283,235 miles of travel, and 112 safety-critical events were identified during the intervention condition which included 439,404 miles of travel. A parametric statistical analysis was used to assess the before and after data.


Safety Benefits

The rate of lane change/merge safety-critical events identified during the baseline and intervention conditions was significantly different (p=0.0824). The intervention phase had nearly 50 percent fewer safety-critical events compared to the baseline phase.

The following data were excerpted from the source report.

Table 1. Summary of results.

Characteristic MeasuredBaseline PeriodIntervention Period
Total number of safety-critical events (SCEs) observed
Total number of blind spot-warning-related SCEs observed
Total amount of validated driving data collected (miles)
Total SCE rate (per 10,000 vehicle miles traveled [VMT])
Blind spot-warning-related SCE rate (per 10,000 VMT)
    Table 2. Summary of system effectiveness.

    Overall SCE Rate ComparisonBaseline Period SCE RateReduction During Intervention PeriodPercent SCE Reduction
    Total SCEs (per 10,000 VMT)
    Blind spot-warning-related SCE rate (per 10,000 VMT)
    Non-parametric Wilcoxon Signed Rank Test ResultsBaseline Period SCE RateReduction During Intervention PeriodPercent SCE Reduction
    Total SCE rate (per 10,000 VMT)
    Blind spot-warning-related SCE rate (per 10,000 VMT)

    * Mean SCE rate difference (p=0.0539)
    ** Mean SCE rate difference (p=0.0824)

    Driver Survey

    Survey results indicated the system was accepted by participants.
    • Seven (7) participants reported the system performed as expected during the four month operational test period
    • Overall, drivers found the system was easy to use, helped eliminate blind spots, and improved their driving performance.
    • Drivers noted that they were comfortable with the glare produced by the visual warnings.


      FMCSA Advanced System Testing Data Acquisition System Highways Program (FLASH DASH)

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    Federal Motor Carrier Safety Administration’s Advanced System Testing Utilizing a Data Acquisition System on the Highways (FAST DASH): Safety Technology Evaluation Project #1 Blindspot Warning: Final Report

    Author: Schaudt, William A., et al.

    Published By: U.S. DOT Federal Motor Carrier Safety Administration

    Source Date: January 2014

    Other Reference Number: Report No. FMCSA-RRT-13-008



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    Metropolitan Areas, Rural Areas, Statewide


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    Benefit ID: 2014-00913