Inside Report (1)

A man who ought to know says the 5-cent-per-gallon gas tax being endorsed by President Reagan is ''laughable.''

The President insists the tax, which could create about 300,000 jobs, mostly in construction, is a legitimate plan to upgrade the nation's infrastructure - and not principally a ''make work'' jobs plan. But John Anderson, who proposed a 50-cent-per-gallon tax during his 1980 presidential campaign, says the $5.5 billion raised each year will not begin to repair the nation's roads and bridges.

Most experts, he says, calculate that such a major public-works program would require $300 billion a year over the next 10 years.m