Here’s the instruction on the website DriversEd.com for coming face-to-face with a vehicle going the wrong way on a one-way street is as follows:

“If you encounter an oncoming vehicle (going the wrong way on one-way street), don’t panic. Slow down and try to get the drivers attention by flashing your headlights and honking your horn loudly. If this does not work, pull over and let it pass.”

That’s easier said (or read) than done.

Have you ever been in that situation? If so, you may agree that remaining calm is a tough option.

When driving the correct way on a one-way street and suddenly a driver turns the wrong way and is heading straight for you, it’s like a lightning bolt from the sky — shocking and dangerous — an unexpected phenomenon that triggers your body’s fight or flight mechanism. Your back stiffens and you feel the shoulder harness tighten. Sweat begins to form on your forehead almost immediately.

You react by yelling. Of course the other driver can’t hear you. But you do it instinctively. Maybe you’ve got that drivers’ ed lesson in the back of your mind from 40 years ago. So you flash your lights or honk your horn. But heck, I don’t blame you if you go into panic mode.

Lately, as I drive the one-way streets in downtown Pasadena on my way home from work or to shopping, restaurants or entertainment venues on weekends, wrong-way drivers are becoming as common as tailgaters on the 210. But much more dangerous.

I’ve seen four near-crashes in the last three weeks due to wrong-way drivers on one-way streets in Pasadena.

In case you are not aware of the layout, a primer. In Pasadena, there are two main east-west streets in which all the vehicular traffic must go only one way. Green Street moves traffic eastbound in three lanes to Pasadena City College. On the western edge of town it gets tricky because there is a portion where Green Street becomes two-way.

The other is Union Street, a westbound one-way street that winds past City Hall, Central Library and into Old Pasadena. (Hint: It’s a fine way to reach Old Pasadena on the weekends because one-way traffic flows easier than on two-way streets. Also, visitors and tourists don’t use it so much so there’ s usually fewer cars and pedestrians crossing.)

The two, one-way streets parallel Colorado Boulevard, the main commercial street. The idea is to allow for more traffic flow on Green and Union. And it works. Most Pasadenans know this, take Green and Union and avoid Colorado Boulevard like the plague.

Pasadena Avenue is a northbound one-way street on the east side of the 710 ditch. St. John Avenue goes one-way (southbound) on the west side of the freeway stub.

While walking to the Ambassador Auditorium Wednesday night on the Green Street sidewalk a car coming from the two-way section of Green turned left into traffic on one-way Saint John Avenue. I gasped. The car’s brakes screeched, barely missing the lineup of cars waiting at the traffic light.

A week before, I was driving on Union Street in the left lane west of Marengo Avenue when a silver sedan turned right from Arroyo Parkway (a two-way street) the wrong way onto Union. He was heading straight at me.

I think I honked my horn. I’m Italian, so I waived my arms after I hit the brakes. A few choice curse left my mouth — in Italian. Luckily, the driver realized his error just in time. Or I might not be here writing this column.

Not long ago on a Saturday night, my wife and I were sitting at a table by the window at The Kitchen, a small Italian restaurant on East Union Street in Old Pasadena. As I sipped my Cabernet, I could see a car traveling south from De Lacey Street turn right (the wrong way) into the one-way traffic on Union. That was a particularly scary near miss because many people walk across Union from the parking garage to reach restaurants in Old Pasadena. So the driver was not only avoiding cars, but pedestrians.

So I ask you: Do we need better signs at these intersections? Just “No right turn” doesn’t cut it. How about bigger “Do Not Enter” or “Wrong Way” signs? I’m at a loss. Perhaps these drivers are from Orange County or the San Fernando Valley where they don’t have many one-way boulevards. They are not familiar with an urban grid with one-way streets.

I’d like to see an alert sent to everyone’s phone as they enter Pasadena city limits that says: “Be mindful of one-way streets.” If that doesn’t work, ticket these fiends or tow their cars.

Steve Scauzillo covers transportation and the environment for the Southern California News Group. He’s a recipient of the Aldo Leopold Award for Distinguished Editorial Writing from The Wilderness Society. Follow him on Twitter and Instagram @stevscaz or email him at sscauzillo@scng.com.