Car accelerating on its own
Hi! First time poster here and am sure hoping you can help....
This morning a very strange and scary thing happened. Less than ten minutes after leaving home, we were driving down the highway, where the speed limit is 70, when suddenly something didn't feel 'right' and I noticed the car was going that fast without my foot even touching the accelerator--it felt like cruise control racing up a hill, only we weren't on an incline, and my car doesn't feature cruise control!--and it didn't seem to want to slow when the brake was applied. In desperation I pushed on the brake pedal hard as it would go, pulled the emergency brake, and got onto the roadside, where I shoved the gear into Park.
I got out and checked that the mats nor anything else were interfering with the accelerator, and when I tried jiggling it, it felt normal.
Hoping it was merely a very weird fluke, we proceeded on our way, and about 10 minutes later the very same thing happened. Only this time it was more difficult to stop, and when thrown into Park, the motor surged loudly and died.
Our mechanic came soon thereafter and checked that cable under the hood that operates the gas. At first he suspected the cable might be fraying and catching, but he checked, and that was fine. He sprayed it with WD-40, and couldn't find anything wrong, so he followed me all the way back home, and of course then the car handled perfectly!
He did caution me, though, that in the event it happens again, to switch the key off and put it into neutral and veer carefully off the road.
Now I'm afraid to drive it, though. Luckily, this occurred on a rural highway. It would've been awful to be in town, surrounded by other vehicles and maybe even people!
I just don't understand it. Plenty of times I've had other cars die on me, but never one try to run off!
By the way, it's a '99 Mercury Tracer.
Thank you for listening!