Last week in the Star Tribune, I was happy to learn that driverless cars actually follow the law to the T ("Welcome to the revolution in personal transportation," Aug. 31). That's better than you can say about most of us. I hope these vehicles will identify themselves clearly to every other driver — and identify the fact that someone is inside who's "just like you and me!"

John Bispala, Minneapolis

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After driving for more than 50 years, I continue to experience anxiety as a passenger in another car, even with my wife driving: too fast, too slow, too close, etc. I can't even imagine acquiescing to a driverless car. While self-driving cars can be programmed to follow the rules of the road, can engineers imagine and provide responses to every possible situation? There could be a lot of carnage in the early stages of this development, as we have already witnessed.

Of course, there is a lot of room for human error in the driving experience, as too many accidents continue to be attributed to impairment, lack of experience, disregard for the law, distracted driving, health complications, failures of nonmaintained vehicles and unforeseen circumstances. Driverless cars will be competing with aggressive drivers who don't obey the laws: speeding, running red lights and stop signs, following too close, and many other infractions. They might get confused and frustrated trying to negotiate traffic by the law.

Hopefully, driverless cars will eventually prove to be a safe, relaxing experience long-term. For now, I will stay behind the wheel as long as I am able-bodied and able-minded.

Michael Tillemans, Minneapolis
WATER USE

Don't shame sprinkler systems, which can be used responsibly

While an Aug. 28 letter writer ("Think hard about your lush lawn") made some excellent points about how to conserve water, the accompanying photograph (reprinted from the Aug. 21 article "Study seeks best ways to curb surge in summer watering," to which the letter writer was referring) gave the impression that lawn sprinkler systems are the culprit. In fact, they are not.

A well-maintained sprinkler system will use less water, because you can control the amount of water and the time the lawn is watered according to the specific needs of your lawn. Intuitive software can modulate watering based on past and predicted future rainfall. The best time to water a lawn is early in the morning, giving the moisture time to soak into the grass roots before sunlight causes major evaporation. A well-maintained sprinkler will save the homeowner time and money (because he or she is paying lower rates at off-peak hours), and will use less water than most traditional methods.

The elephant in the room that no one is willing to talk about is that sprinkler systems and the more traditional methods have not yet adequately addressed the problem of back-siphonage. All homes are required to have devices preventing back flow to keep contaminated water out of municipal water supplies; however, there is little regulation about the water that is attached to your home water meter and it could back-siphon into your home.

Reputable sprinkler installers will install backflow prevention devices and will inspect them periodically. The same cannot be said for homeowners who sprinkle their lawn with a hose laying out in the warm sun all day or, worse yet, have that same hose hooked up to a bottle to dispense fertilizer or control pests.

If homeowners had unlimited time to devote to their yards, they could reduce their water use to near zero by installing rain barrels and cisterns, and by mulching and composting their gardens. Then again, they would have to control mosquitoes (a few drops of vegetable oil on the surface of the water in the rain barrel or cistern) and develop ways of applying this water where it is needed most efficiently.

Before you go blaming and shaming homeowners who have sprinkler systems because they do not want to be a slave to their yard, talk to the experts in that watershed district to find out what the problems really are, and how they can best be addressed.

Benjamin Cherryhomes, Hastings
FIGHTING POLIO

The last step toward eradication is diplomacy, not duplicity

Charles Adams Cogan's Sept. 2 commentary on the recurrence of polio in Nigeria ("Nearly eradicated worldwide — nearly") was welcome but incomplete. It's no surprise that polio's last stand is in regions hostile to U.S. policy. Public health vaccination efforts in Nigeria, Pakistan and Afghanistan are complicated by a belief that U.S. intelligence agents are masquerading as public health workers, a belief legitimized by the capture of Osama bin Laden.

Hillary Clinton, as secretary of state, participated in the use of an agent disguised as a vaccinator to locate Bin Laden and in the decision to brag about it afterward. Both she and Donald Trump support using international public health initiatives as cover for intelligence activities.

It is past time for both parties to renounce this practice, which sabotages the fight against endemic diseases — enemies that have killed far more people than terrorism.

Tim Cooper, Eagan
GENDER LABELS

Culture, language in progress, not meant to be trivialized

The Aug. 27 "News of the Weird" column in the Variety section compared transgender people to Bulgarian vampire tourism, ill-behaved celebrities and police reports about "rednecks" (a classist characterization in its own right). The full column on the author's website gets worse.

It's not "weird" that an Australian study is asking participants to place themselves within 33 different gender-identity labels. The trans community is enjoying spirited discussion and rapid evolution of the terms we use to describe and understand ourselves in relation to a world that is somehow divided by the two most common groups of physical sex characteristics. This is just culture and language at work.

Many of us are relieved to find or create terms that summarize a tangle of feelings and experiences that our cisgender friends and family have never had to navigate. It can dispel the self-doubt and loneliness of thinking that no one else understands what you're going through. This trans woman is insulted by the implication that we're weirdos making up new words to feel special.

Erika von Kampen, Minneapolis
'ON THE WING' COLUMN

Finally, pigeons get their due

I was happy to see Jim Williams singing the praises of the pigeon ("On the Wing" column, Variety, Aug. 31). These intelligent birds have been disparaged as "flying rats" for too long. In addition to their exquisite beauty and important contributions to scientific discovery, they have bravely served during wartime. Thirty-two pigeons (more than horses, dogs and a single cat combined) have been awarded the Dickin Medal for conspicuous gallantry and devotion to duty. Many thousands lost their lives delivering vital messages to troops in World Wars I and II.

A pigeon named GI Joe flew 20 miles in as many minutes, delivering a message credited with saving 1,000 villagers and British troops in Calvi Vecchia, Italy, in World War II. A message delivered by William of Orange saved more than 2,000 soldiers during the Battle of Arnhem in September 1944. On Oct. 3, 1918, Cher Ami delivered this harrowing message to allied troops: "We are along the road parallel to 276.4. Our own artillery is dropping a barrage directly on us. For heaven's sake, stop it." Shot through the breast, blinded in one eye, covered in blood, with a leg hanging only by a tendon, she flew 25 miles in 25 minutes, helping to save the 194 surviving soldiers trapped behind enemy lines.

Next time you're tempted to belittle the lowly pigeon, think for a moment of Cher Ami. She was truly named: Dear Friend.

Kristin Heiberg, Minneapolis