Why did the tarantula cross the road?

We just had a great long weekend driving to New Mexico (Taos to be precise) and back again. More on that later!

On the way home I saw a slow moving black thing walking on the road. It looked rather like a large spider - low slung, definitely moving like a spider. I tried to miss it but I fear I left a splat on the road. Then another one just over the crest of a hill, so it bit the dust too.

Alas I killed off two male tarantulas. I didn't mean to or aim to do it - even spiders in the middle of nowhere have a right to live. Why were they crossing the road? This little tale will reveal all..... (for the spider phobic there *are* pics of tarantulas on that page)