Every day during rush hour, thousands of people are forced to merge from one traffic lane to another, frequently in stop-and-go situations where the ability to reach the desired lane depends on the generosity of someone already in that lane.

My problem occurs after I am in my lane, ahead of the generous person who let me in, and I have the option of letting others in ahead of me or of moving up and refusing to do so.

My wife says that since I was dealt with generously and politely, I have the obligation to do likewise to others. That's fine, I guess, but it seems to me that to do so is to be rude to the person who let me in. My generosity would simply add seconds (or minutes, at some lights) to his or her trip, and that seems a poor recompense.

Finally, is it forgivable to deny access to those who abuse other motorists by speeding to the very end of the lane that has to merge, declining to enter the flow until long after the need and opportunity to do so made itself apparent?

A: Miss Manners thoroughly dislikes situations that are set up so that what people reasonably expect depends on the generosity, as you call it, of others.

That is why she would dearly like to abolish the custom of tipping. Honest laborers have the right to expect their full wages to be paid regardless of the whims of the customers. (In cases where service is poor, the customer should complain.)

All too often, such opportunities to decide whether another person really merits sacrificing one's own immediate interests encourage petty tyranny. It's only a highway, you know, or, in the case of tipping, a restaurant or a hotel -- not the Place of Judgment with you being asked to preside.

There is no reason that you should feel bloated with self-satisfaction if you cooperate with traffic patterns, or so grateful to others who do so that you wish to reward them by cutting off new supplicants. For goodness' sake, just let everybody get home, will you?

Miss Manners thinks it futile to attempt to administer punishment to drivers who try to take advantage of the system. Without claiming that justice is always done anyway to rule-breakers, she will point out that daring drivers are more likely than most to suffer unfortunate consequences.

But she acknowledges that no one driver has to permit every car to go ahead, and will look the other way if the discourteous drivers are the ones you choose not to admit.