Pardon my terrible photo!!
I created a masking tape road on a canvas drop cloth. Kiddo loves organizing his toy vehicles on it.
It was another idea from DIY Distractions. (That book has become so handy!) You can see the cat enjoyed it, too -- or is that the grated cheese Kiddo spilled? Hmmmm. Anyhow, it worked like a charm and kept him occupied for some time, as did making some contact paper collage.
More ideas for toy cars: