ISLE OF MAN —It's no secret the Isle of Man's TT is dangerous. Just ask The Doctor, seven-time MotoGP star Valentino Rossi. The Italian told Top Gear magazine, "I did a lap of the Isle of Man, and I understand why people love this because it's f**king awesome—it's unbelievable, great. But, unfortunately, it's too dangerous. The Isle of Man is very difficult. If you make a mistake, maybe it's the last mistake."

Still, every late May through early June—we were there last week—the entry list is full. The evening streets of the nearby city of Douglas are crowded with spectators who that day were at the likes of the Black Hut, Sarah's Cottage, and The Thirty Third viewing areas to watch the motorcycles or sidecars flash by.

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Or, on occasion, a Subaru. The four-wheeled machine was driven by rally champ Mark Higgins , and this year it was a very special Subaru indeed. Created by Prodrive, Higgins drove a 600-horsepower WRX STI to a 128.73-mph average speed during one lap of the circuit, quick enough to put him in the top-10 motorcycle times.

Higgins, an Isle of Man native, is quite aware of the joy of a fast lap around the 37.7-mile course—and also its risks. He clued us in to the event's most dangerous dozen:

SPEED: "It's just an insane speed compared to any other circuit. The bikes are doing 200 mph. "

NO RUNOFF: Not only are the speeds insane, but a rider will find himself or herself racing past brick walls, telephone poles, and houses, some of which are in villages.

PROXIMITY: Normally mundane features like curbs can easily trip a motorcycle.

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IT'S A LIVING TRACK: "It's changing all the time," Higgins explains. "Every time you go out, there could be leaves on the road. Oil that's been put down. You talk about tracks rubbering in, well we've got road traffic one day and we race the next, so it's changing, never the same, and you have to account for that. "

ANIMALS: "Rabbits and birds … hit one of those at 180 mph and the bird doesn't come off very well—or the rider. One guy lost an arm when a small rabbit hit his sidecar. "

MECHANICAL FAILURE: "It could be mechanical or a tire blow out." And it could also occur at 200 mph in an area with, you guessed it, little or no runoff.

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MARGIN OF ERROR: This falls on the human side and, as Higgins points out, "There is none. "

RIDERS AND BACKMARKERS: "You are in your zone doing 200 mph and you don't think there's somebody coming past you; you've got your line and they are committed. That has created issues. "

LACK OF PROTECTION FOR RIDERS: Higgins simply points out, "A piece of leather and a helmet. "

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WEATHER: Higgins explains this is an historical reason. "Today they would never run it when it's foggy or wet, but in the old days (the race is more than 100 years old) you could have fog on the mountain, and rain, and off you go. "

TRADITION: "If they tried to set this course up now as a new thing it would never be allowed." But the TT's challenge, lure, and tradition bring riders back each year.

REALITY: "The likelihood of death. It could be your last race. "

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"It's a perfect test for man and machine," Higgins says of the TT. "The whole thing of having people waiting in the pits … it's all very gladiatorial for the bike guys. Watch how people say goodbye to people. Watch the crews, there's fear when people go out there on the track. More so for the riders and families because the riders are doing what they love, but some don't come back. It's the most amazing place in the world. It's addictive."

And deadly. This year, five competitors died in crashes. Will those deaths stop the TT? No, and it doesn't hurt to have been there and met the people and felt the passion of the place to understand why. To many, the energy, the history, and the enthusiasm of the TT makes nothing but sense. Of the circuit Higgins figures, "There's nowhere like it in the world in terms of speed and spectators. The atmosphere the spectators give you as a competitor is very special."

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And then the rally driver adds, "The riders are my heroes. I look up to them because I think what they do on those bikes is absolutely incredible. John McGinnis, Ian Hutchinson, and they are friends as well. I have the upmost respect for those guys and they are the most normal, nicest people you'll ever meet.

"True heroes."

Photos courtesy of Isle of Man TT and Subaru