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Carrier Intervention Effectiveness Model

The Carrier Intervention Effectiveness Model (CIEM) provides FMCSA with a tool for measuring the safety benefits of carrier interventions, measuring the direct impact of interventions on carriers that received them. The CIEM is based on data from the individual and cumulative "before and after" changes in the safety performance of carriers that received interventions in a given year. The model compares motor carriers’ crash rates in the 12 months following an intervention to their crash rates in the 12 months prior to the intervention. This change in crash rates is adjusted for the observed change in crash rates for carriers not receiving interventions.

The CIEM incorporates data collected from compliance reviews (CRs) and other carrier interventions, including warning letters, offsite investigations, onsite focused investigations, and onsite comprehensive investigations. The CIEM yields national-level measurements that estimate the effectiveness of FMCSA’s carrier interventions.

To learn more about the CIEM and the effectiveness of FMCSA carrier interventions, view the CIEM reports found here.

–>View Model Reports
Carrier Intervention Effectiveness Model - National Results
FY 2009FY 2010FY 2011
Total Interventions28,33131,37258,230
CSA Warning Letter2,1845,79039,004
PRISM Warning Letter7,5007,4151,764
Offsite Investigation345456375
Onsite Focused Investigation5201,2076,279
Onsite Comprehensive Investigation3868291,399
Compliance Review16,51714,5778,274
Non-Rated Review8791,0981,135
Adjusted Crash Rate Reduction by Carrier Size Group
1-5 PUs34.5%29.3%28.8%
6-20 PUs20.3%13.9%30.0%
21-100 PUs7.2%-2.1%*15.9%
>100 PUs-0.2%*-4.9%*3.2%*
Estimated Benefits
Crashes Prevented2,3981,6856,145
Injuries Prevented1,5081,0513,774
Lives Saved8055201
Negative crash rate reductions indicate increases in crash rates.
*Non-statistically significant adjusted reduction.
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