The Federal Motor Carrier Safety Administration has proper safety controls in place for Mexican carriers operating across the border, but the pilot program to test the system has too few participants to project the outcome of a full border opening.

So says the Department of Transportation’s Inspector General in an audit of the program.

The Inspector General’s audit is the latest chapter in a 15-year effort to open the Mexican border to long-distance trucking, as required under the North American Free Trade Agreement.

For the past three years FMCSA has been refining a qualification and inspection program for a limited number of Mexican carriers in an attempt to prove that it can establish and enforce a safety regime.

The pilot program ended in October, and the agency granted operating authority to the 13 carriers that had been participating.

The agency concluded that the Mexican carriers in the program and Mexican carriers that already have U.S. authority were as safe or safer than U.S. or Canadian carriers.

The Mexican carriers in the pilot program had much lower driver and vehicle out-of-service rates than U.S. or Canadian carriers.

Their driver OOS rate was 0.2% compared to 5.3% for U.S. carriers and 3.7% for Canadian carriers. Their vehicle OOS rate was 8.9% compared to 22% for U.S. carriers and 12.5% for Canadian carriers.

The Inspector General found that the agency set up adequate enforcement and monitoring systems, and was able to determine that the pilot program did not harm safety.

But there were not enough carriers in the pilot program to produce a statistically valid projection for all Mexican carriers that may qualify for such operations in the future, the Inspector General said.

The Inspector General’s report is not likely to alter the long-standing dynamics of this issue.

Supporters of an open border, including American Trucking Associations, will be able to point to the success of FMCSA’s safety program. Those who oppose free trade, including the Owner-Operator Independent Drivers Association and the Teamsters union, will be able to say the program does not justify an expansion of the cross-border trade.