Times change, and sometimes federal rules attempt to change with them -- with varying results. Take the question of how to ensure the safe transportation of migratory workers.It's a story laid out in part in the Aug. 4 Federal Register (page 51625).

More than 25 years ago a series of television and print exposes described mistreatment of migrant laborers. They included highly publicized stories of accidents that killed or injured hundreds of these workers as they traveled from job to job.

One result of these disclosures was a series of regulations by the Interstate Commerce Commission in 1957 that focused on the trucks, buses and tractor-trialers used by the migratory labor contractors in those days.

The ICC set medical requirements for the drivers of these vehicles, and equipment was specified.

For example, seats had to be at least 13 inches deep, with at least 24 inches of space between headrests. The seats had to be without cracks more than two inches wide, and if made of wood, "planed or sanded smooth and free of splinters." Even standards for meal stops were set -- every six hours and for at least 30 minutes.

In 1967 responsibility for the rules was transferred to the Department of Transportation.

Twenty years after the first ICC regulations went into effect, DOT in 1977 hired a private consulting firm to look at how the old rules affected today's migratory laborers.

To do the study, the contractor drew up a questionaire and interview schedule for traveling farm workers. It was done even though the contractor knew according to a later report, that "no one is certain how many persons regularly cross a state or natural boundry" to work on farms.

In one of the regular ironies found in federal government operations, the Office of Management and Budget, which must approve all federal questionaires, blocked this one on the grounds that there was no established universe of migratory workers or their vehicles against which the contractor's data could be compared.

Barred from using his questionaire, the consultant arbitrarily picked 32 sites in 11 states that he said followed the "farm stream." From those sites he counted the vehicles used by migratory workers -- not the most scientific of statistical methods.

Nonetheless, he came up with what he called "a major change" in the way migratory workers travel. Buses and trucks -- those regulated by the DOT rules -- had all but vanished. Instead, the farm laborers and their families were now traveling in their own pickup trucks, recreational vehicles and station wagons as they went from job to job.

The study found that they could purchase these vehicles since "migrant income has increased in recent years." At the same time, the high cost of insurance premiums on vehicles carrying large numbers of migrant workers" have led to a sharp decline in their use by farm labor contractors.

What is DOT's Federal Highway Administration, which enforces the migratory workers transport rules, to do, faced with such a situation? It's now almost two years since the consultant's report was filed, and FHA has decided to see if some modifications -- even revocation -- of the rule may be needed.

The Federal Register notice to the public for comment raised questions about whether transportation of these workers under the rules "should be allowed to continue" and whether the need for "more stringent inspection and maintenance requirements" is there.

There was no question on whether safety requirements should be transferred to those vehicles the survey found were now most used by migratory workers, that is, station wagons, recreational vehicles and family-owned pickup trucks, since, as one official said, FHA "doesn't regulate them."