The top transport officials from the United States, Canada and Mexico said they have made considerable progress in developing greater compatibility of trucking standards under the North American Free Trade Agreement.

Meeting in Montreal Tuesday while the 20th World Road Congress was taking place in Montreal, U.S. Transportation Secretary Federico Pena, Canadian Transport Minister Doug Young and Mexican Transportation Secretary Carlos Ruiz Sacristan reviewed outstanding issues in the continental trucking area.Under Nafta's transportation provisions, the first phase of liberalized access and investment is to take effect on Dec. 17.

Starting that day, U.S. and Canadian motor carriers will be allowed to make cross-border deliveries into Mexican border states. The United States also will allow Mexican truckers access to its border states, notably California and Texas.

The three countries have reached harmonization agreements on such matters as safety and traffic signs and the issuing of licenses, but remain far apart on achieving common standards on truck weights and dimensions.

A press release said each of the ministers recognized that the process of regulatory compatibility was a long-term effort that would extend beyond Dec. 17.

"In those areas where compatibility cannot be achieved, regulations of the country in which operations are being conducted will continue to be honored," the press release said.

"We haven't reached paradise on earth insofar as the truckers are concerned, but we are heading in the right direction," said Mr. Young, who added that lines at the Mexican-U.S. border will be reduced.

Nafta working groups recently agreed on minimum standards for "mechanical fitness" that commercial vehicles must meet to operate in the United States, Canada or Mexico. The groups are currently developing common vehicle- inspection standards.

According to the press release, the three countries have determined that the relevant rail regulations affecting cross-border traffic are largely compatible, and they are examining prospects for still greater compatibility where appropriate.

The next Nafta ministerial transport meeting is scheduled for March.