Answer Man

Why does the mirror on the passenger side of a car make everything look smaller?

Q: Why do cars have a standard mirror on the driver’s side and a fun-house type mirror that makes everything smaller on the passenger side? I mean, they have to remind you that objects you see are really closer than they appear. Doesn’t this make driving extra dangerous for those who do not or forget to compensate?

C.S., of New Athens

A: Mirror, mirror on the car, which lets us see best both near and far?

If you do any research on the internet, you wouldn’t be surprised to find that there has been a battle waged over this very question for years. Some say that odd mirror on the passenger’s side is the best thing since the sliced raisin bagel. In fact, there has been moves to allow manufacturers to put them on both sides of the car.

Others complain the distorted view they give is an accident waiting to happen. As I usually do, I’ll try to give you the best of both sides and let you decide:

In scientific terms, the driver’s side mirror is usually a plane mirror with a flat, reflective surface (although that has changed, but more on that in a minute). Simply put, they produce a virtual image that is of the same shape and relative size as the object it is reflecting.

On the other hand, convex mirrors bulge at the center and then curve away from the image they are reflecting. In doing so, they can reflect a larger field of view with the same size mirror at the cost of making the objects they reflect appear smaller than they would otherwise.

Most experts seem to agree that such a mirror is necessary on the passenger side. They say it is so far from the driver that a plane mirror would not produce a large enough field of view to allow switching lanes to the right safely. Drivers simply have to take into account that they’re getting a slightly distorted view and adjust accordingly.

But that seems to be where the agreement ends.

In the United States, manufacturers by law still must place a plane mirror on the driver’s side, but some continue to fight for the European model of wide-angle mirrors on both sides. They say it would give drivers a more comprehensive view to their left without the frequent or, at least, occasional turn of the head to make sure nobody is in their blind spot.

“What’s the big deal?” Eric Taub asked in a 2010 op-ed piece in the New York Times. “With two convex mirrors, blind spots are virtually eliminated, obviating the need to twist one’s head toward the left when looking to turn left or changing lanes to pass. Having driven for years in Europe, I have never seen a car with a flat driver’s mirror.”

Not so fast, say others.

“Firstly there is a visual difference between looking down the road and looking in the mirror which requires the eye to adjust to a different focal reference, which can cause confusion and a delay in response,” argues Ernest Litera, of the Royal Automobile Club of Victoria (Australia). “Secondly the vision is distorted and the other car is actually closer than it appears, which can result in close calls or misjudgment of traffic when making lane changes.

“At night the mirror exaggerates the headlights of following vehicles, which can cause dazzling and also a delay in eyes adjusting to the lights. And, finally, any raindrops on a convex mirror are severely distorted and can completely negate the mirror’s function altogether, so you have no rear view mirror.”

A 1996 University of Michigan study, however, found such mirrors to be of benefit, especially to those at highest risk of accidents. It concluded that, although not statistically significant, convex driver’s-side mirrors actually tended to reduce the chances of lane-change mishaps on the driver’s side. Moreover, they tended to be of particular help to both young drivers and senior citizens.

Baby steps have been taken to change the law. As early as 2007, Lamb was told by a National Highway Traffic Safety Administration official that the agency would “consider” permitting convex driver’s-side mirrors, although no change has yet been made despite a later petition by manufacturers that included General Motors and Mercedes-Benz.

In the meantime, some manufacturers began offering hybrid driver’s-side mirrors — part plane, part convex. It’s apparently legal as long as the old-fashioned flat mirror remains part of it. And there may be even better compromises ahead. In 2012, Dr. R. Andrew Hicks, a Drexel University mathematics professor, patented a mirror that can give a much wider field of view with only minor distortions of shapes and straight lines. Whether you’ll ever see one on a future car, however, remains to be seen.

Q: What is happening with the Fresh Thyme store that is supposed to open in June in Edwardsville? They cut some trees and then stopped. No activity on the land. Can you give us an update?

Carol B. Dappert

A: Nobody wishes I could more than Walter Williams, the city’s economic development director. Like you, he remembers how excited he was when the announcement was made and a little preliminary work was done.

Since then, he has heard nothing, and neither have I. For the past three weeks, I have left several messages by phone and email on the company’s website without response, so we have to assume the project is dead for now. It had been expected to anchor the growing complex on Illinois 157 south of Governor’s Parkway and across from the entrance to Southern Illinois University Edwardsville.

Today’s trivia

How long have people been making mirrors?

Answer to Sunday’s trivia: On Dec. 4, 1971, the rock band Deep Purple was in Montreux, Switzerland, ready to record an album using a mobile recording studio it had rented from the Rolling Stones. On the eve of the recording session, a fire broke out at the Montreux Casino during a concert by Frank Zappa and the Mothers of Invention. Fortunately, there were no major injuries, but the entire casino complex was destroyed, which inspired Deep Purple to write “Smoke on the Water” after seeing smoke from the fire spread over Lake Geneva. In 2004, the song was listed at No. 434 on Rolling Stone magazine’s top 500 of all time. Surprisingly, though, Ritchie Blackmore later claimed fans of the band thought his famous opening guitar riff as too simplistic. In response, Blackmore told them to think about the simple four-note arrangement that opens Beethoven’s 5th Symphony.

Roger Schlueter: 618-239-2465, @RogerAnswer

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