not passing 20mph

Today on my way to work, my spedometer was reading 20mph with my foot on the gass (all the way down and i was going 20mph), plus the car was shaking. When i stopped at the stop light, the spedometer was reading 10mph. However, next stop light my car was normal.

I only have 70,000 on my 1995 grand am se, with an automatic 2.3L

Is this a future sign of a going transmission?
Is there another problem, besides the transmission?
THis sucks

Was the engine revving a lot or was it having a hard time picking up? If the engine wouldn't rev check the cat. it may be blocked. If the engine was revving and you weren't going anywhere then I would suspect the tranny!

it wasn't reving!!!!

Since it wasn't revving I would check the following. 1. Throttle position sensor
2. Fuel Pressure, Fuel Filter
3. Coils
4. Cat. If blocked the car will act like it is congested and will not want to rev.

It doesn't sound like the tranny is bad since the engine was not revving when you were trying to drive. If it was in the tranny the engine would rev and the car would not move.

thank god its not the tranny

check tranny fluid sometimes when low car wont go to fast when steping on gas.