Which Anova for this situation.

I am trying to analyze the speeds of vehicles driving over four different road conditions: Down a steep slope, up that steep slope, down a gentle slope and up that gentle slope. I observed 80 cars and 30 trucks. So I have 2 levels (trucks and cars) and 4 blocks (the different surfaces). But, I have different numbers of cars and trucks. What sort of an anova2 deals with this situation?