Regarding "Mr. Nestor on 'Nestoring' " {letter, Oct. 19}: There may be people in addition to John O. Nestor who do not find "obnoxious" the practice of blocking highways by driving on the left at 55 mph. I, however, prefer to leave law enforcement to the police, except in situations when commission of a felony is imminent and no police are around. There is something about this putative vigilantism that seems alien to the public good, however much it may be justified by and gratify its practitioners -- most of whom, I suspect, are merely thoughtless or negligent when they block the road by driving on the left.

RICHARD G. AUGENBLICK Arlington

John Nestor says he knows his practice of driving in the left lane at 55 and refusing to let speeders pass is legal, because he asked various state agencies about it when he started doing this several years ago. I do not know when he began, so I cannot say whether it was legal then. As a lawyer, however, I can assure Mr. Nestor that, whatever the legality of "Nestoring" when he began, overtaking vehicles should be allowed to pass. This duty does not depend on how fast the overtaken vehicle is going (after all, this is a safety statute, not a "keep-the-jerks-from-speeding" statute). Failure to pull right is a traffic infraction; Mr. Nestor can expect to pay $44 for each ticket he gets.

The more important issue is that what Mr. Nestor is doing is dangerous. Mr. Nestor points out that two-thirds of all Beltway accidents are caused by lane changes but goes on to say, "Let {speeders swerving around him} take the risk." He also claims he is not arrogant. The two statements contradict each other.

Mr. Nestor has given no thought to everyone else on the highway. He has appointed himself to enforce the speed limit with no care about what this might mean for the innocent driver. When a speeder swerves around Mr. Nestor, risk is created, not only for the speeder, but for everyone in the vicinity.

As anyone who drives the Beltway can attest, speeders commonly weave around slower vehicles in their way. Indeed, Mr. Nestor has known speeders to swerve around him and jam on their brakes in front of him, apparently as a form of punishment. This practice (anti-Nestoring?) is both dangerous and illegal. The point here is that it is also predictable and preventable. Mr. Nestor knows this dangerous behavior will happen, yet he persists in conduct calculated to provoke it.

All Mr. Nestor has to do to be safe is keep right except to pass. The reckless speeders would then be on their way with no risk to Mr. Nestor or the innocents around him. A responsible member of society could do no less. MICHAEL W. TOMPKINS Arlington