he harbor trucking environment has been calm for the past month.

Independent truckers whose demonstrations interrupted cargo handling during the summer at Seattle-Tacoma, Baltimore and Vancouver, British Columbia, have taken no job actions lately. The drivers in Vancouver achieved their objectives of better pay and working conditions. Harbor truckers in the United States appear to be regrouping before their next offensive.With the peak shipping season over now, it would be easy for shipping executives and terminal operators to think their problems are over. That would be a big mistake.

Cargo volumes are tapering off now, but they will increase again next year, and with them will come congestion at marine terminals. The maritime industry should make use of the slack season to address the productivity issues at marine terminals that led to the trucker uprisings earlier this year.

The job actions brought attention to the inequities at container ports. While shipping-line employees, terminal operators and longshore workers earn comfortable, middle-class or upper-middle-class wages, the owner-operator truck drivers who shuttle containers to and from the marine terminals struggle to make a living.

Harbor truck drivers get paid by the trip. They aren't compensated while they sit in line at congested marine terminals. Ship lines, terminal operators and longshore workers can help these drivers get the number of round trips they need each day - and enhance their own efficiency - by improving productivity at the marine terminal gates.

Some terminal operators in Los Angeles-Long Beach, the nation's largest port complex, regularly ran early-morning ''hoot owl'' gates during the peak shipping season. Terminals also staggered lunch hours and longshore workers' coffee breaks so the gates remained open consistently from early morning until evening.

Trucking companies that called at these terminals said the lines were shorter and their drivers got the three or four turns they needed each day to pay their truck expenses and earn a profit.

True, running extended gate hours is costly. The alternative, however, is for frustrated drivers to boycott the ports. From that perspective, the extended gates are a wise investment.

There are other, more ambitious steps that can be taken to improve productivity in harbor trucking. Establishing an electronic communication system linking trucking companies, marine terminals and customs brokers in a real-time environment would streamline gate operations. Ports could also establish general-user off-dock yards where empty containers can be dropped off. This would reduce congestion at marine terminals.

When terminal operators were pressed during the peak season to get their containers off the piers, they paid higher trucking rates to ensure there were enough drivers. Some terminals provided free lunches for the drivers. Some even paid drivers waiting time when lines were long. But with the peak season over, those bonus payments are history.

The measures that reduced congestion at marine terminals during the peak season improved gate productivity. If independent drivers are satisfied with their pay and working conditions, they won't boycott the ports and they won't go to the unions to be organized.

The Teamsters union knows that. A port Teamster official in Los Angeles-Long Beach told a group of harbor transportation executives recently, ''We don't organize these guys. You organize them for us.''

If unions can successfully organize independent drivers, they will probably be paid by the hour, as they are now in Vancouver. Then drivers wouldn't complain about sitting idle in long lines, and productivity at marine terminals would decline further. And the harbor trucking rates would go up an estimated 35 percent to 45 percent.

Shipping lines and marine terminal operators have a choice. They can extend terminal hours, implement improved communications systems and pay higher trucking rates so drivers will be better compensated. Or they can do nothing and wait for the trouble to start over again next year.

Shipping lines and terminal operators will pay a price either way. But it's far more sensible to invest in productivity than to pay to correct problems after they occur.