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About the Authors

Trucksafe's President Brandon Wiseman and Vice President Jerad Childress are transportation attorneys who have represented and advised hundreds of motor carriers (both large and small) on DOT regulatory compliance. Brandon and Jerad are regular speakers at industry events and routinely contribute to industry publications. They are devoted to helping carriers develop state-of-the-art safety programs, through personalized consulting services and relevant training resources. 

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What is the Inspection Selection System?

I've lost count of the number of times carriers have approached me believing their trucks and drivers were being specifically and unfairly targeted by law enforcement for inspection. Often, they're convinced that a particular officer or agency has it out for them and they're looking for guidance on how to put an end to it. The first question I ask these carriers is "what's your Inspection Selection System (ISS) score?" And too many times their response is "what's an ISS score?"

Simply put, the Inspection Selection System is part of the FMCSA's Compliance, Safety, Accountability program and helps the agency and its state partners prioritize carriers for enforcement by generating roadside inspection recommendations based primarily on violation data. Carriers with higher ISS scores will be targeted for more frequent roadside inspections.

In this article, we'll take a closer look at ISS, including how it scores carriers, what data factors into the scoring, the consequences of high scores, and how carriers can improve their score.

The purpose of ISS

The FMCSA is a relatively small agency, yet it is tasked with regulating the nearly 600,000 active motor carriers that operate in the U.S. In light of this, the agency relies on a number of systems and data to help it prioritize carriers for enforcement. The CSA program is one such system, and it tends to get the most attention; however, there are others, including ISS.

The FMCSA describes ISS as a system "used at roadside inspection stations to help inspectors identify and prioritize motor carriers for safety inspections." Similar to CSA, its purpose is to target carriers with compliance problems and put them through additional inspections to identify additional gaps. But while CSA is geared towards prioritizing carriers for compliance reviews, ISS is aimed at targeting carriers for more frequent roadside inspections.

Understanding the ISS scoring scale

ISS scores every registered motor carrier on a scale of 1 to 100. It then assigns them an inspection recommendation of "Pass," "Optional," or "Inspect" based on their score.

As shown in the table below, carriers with an ISS score of between 1 and 49 fall in the "Pass" category, meaning that, based on their satisfactory compliance history, roadside inspections are not warranted. Carriers with a score of between 50 and 74 are in the "Optional" category, meaning that more frequent roadside inspections are warranted based on prior violations. And carriers with an ISS score of 75 to 100 are in the mandatory "Inspect" category, meaning their vehicles are given top priority by law enforcement for roadside inspections.

ISS Table

More often than not, carriers who feel their trucks are being unfairly targeted for inspection will come to find their ISS score falls in the mandatory "Inspect" category.

How are ISS scores calculated?

ISS relies heavily, but not entirely, on data from the FMCSA's CSA system to calculate a carrier's ISS score. If you're not familiar with the CSA system or how it functions, be sure to check out our prior article at this link. In short, the CSA system assigns carriers percentile ranks in 7 categories known as the BASICs. Carriers whose percentile scores in one or more BASIC exceed certain "intervention thresholds" on a particular month are prioritized for enforcement.

For its part, the ISS has two scoring methodologies, which the FMCSA details in this document: a Safety Algorithm and an Insufficient Data Algorithm. The Safety Algorithm "prioritizes carriers by assigning an inspection recommendation and value to carriers with sufficient data to receive a percentile ranking in the FMCSA’s SMS. Additionally, the Safety Algorithm assigns an inspection recommendation and value to carriers where a Safety Investigator has found a Serious Violation during an investigation in the preceding 12 months. The Safety Algorithm assigns inspection recommendations of ‘Inspect’, ‘Optional’ or ‘Pass.’" On the other hand, the Insufficient Data Algorithm "assesses all other carriers that were not assessed by the aforementioned Safety Algorithm. The Insufficient Data Algorithm assigns inspection recommendations of ‘Inspect’ or ‘Optional.’" Carriers who are under a company-wide out-of-service order due to serious violations are placed in the mandatory "Inspect" category and assigned an ISS score of 100, regardless of which algorithm they would otherwise fall under.

The Safety Algorithm

The Safety Algorithm raises the prioritization of carriers whose compliance problems can be effectively addressed roadside. Of the 7 BASICs, the FMCSA has determined the following encompass issues that can be addressed roadside: Hours of Service, Driver Fitness, Drug/Alcohol, Vehicle Maintenance, and Hazmat. ISS then prioritizes carriers with elevated scores in these BASICs according to the following chart:

Safety Algorithm Chart

In short, and putting aside those with active out-of-service orders, carriers with two or more BASICs (one of which is best addressed roadside) that exceed the applicable intervention threshold will be placed in the mandatory "Inspect" category, as well as carriers whose Hours of Service BASIC is in alert status. The Safety Algorithm also takes "serious violations" (i.e., acute and critical violations discovered during a compliance review) into consideration, such that a serious violation in a BASIC sets the percentile to 100.

Lastly, ISS places "high-risk carriers" in the mandatory "Inspect" category. According to the ISS methodology, a "high-risk carrier" is one displaying the following characteristics:

  • Four or more BASICs exceeding the threshold ; or

  • Both of the following: A) two or more total BASICs exceeding the threshold and B) one of those BASICs exceeding the threshold is in Unsafe Driving, HOS Compliance , or Crash Indicator with BASIC percentile >= 85.

Insufficient Data Algorithm

ISS scores for carriers who lack sufficient roadside inspection or compliance review data to generate CSA scores are calculated under the Insufficient Data Algorithm. FMCSA explains, "the underlying concept is to encourage inspections when there is little or no recent inspection or crash activity." Thus all carriers who have insufficient CSA data are given an "Optional" recommendation, except for a certain number that are randomly selected for an "Inspect" recommendation. The following chart details this algorithm:

Insufficient Data Algorithm Chart

Improving ISS scores

Unfortunately, there's really no secret formula for improving ISS scores; it takes time and effort on the carrier's part to improve the scores over time. As a general rule, ISS scores improve through improvements to the carrier's underlying CSA scores. For example, a carrier that currently has two BASICs in alert status will typically be in the mandatory "Inspect" category. However, if that carrier is able to improve one of the BASIC scores such that it is no longer in alert status--and assuming the remaining BASIC that's in alert status is not Hours of Service--the carrier may very well progress into the "Optional" category.

Of course, improving BASIC scores is not an easy task. In a prior article, we provided five proven tips for improving CSA scores. We've also discussed how carriers can leverage the DataQs system to help them improve their scores.

In short, incurring fewer violations over time is the solution. Accomplishing this takes a good amount of analysis and discipline on the carrier's part. Carriers should be routinely monitoring their roadside violations and taking remedial action to address them with their drivers. As the number and severity of violations decrease, so too do carriers' CSA and ISS scores.


ISS scores, like CSA scores, are an important metric that carriers should be tracking on a regular basis and consistently working to improve. If you need assistance analyzing your scores or working to improve them, please feel free to reach out. And if you're interested in more in-depth training on DOT safety regulations, be sure to check out our comprehensive, online training courses at Trucksafe Academy.


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