No Gary, the road is off limits to walkers, joggers, runners and everything else except motor vehicles and bikes by special permit.
The Pikes Peak Marathon starts in Manitou Springs 6300', up a paved road for about a mile and then on the Barr Trail which is your typical dirt rocky trail. It is far from being a gentle slope but is every bit as challenging, a rocky gnarly trail as you describe Whitney, only longer and with more elevation gain to the summit vs Whitney from the Portal.
Instead of speculating, come on out next summer en route to Whitney and get some altitude training in here !!
Well in that case, Ernie, it would have to be Pikes with significantly more elevation gain and a longer distance. I assumed the Pikes Marathon would have been on the road - once again, ass-u-me strikes! Someone needs to do both "marathons" and report back to us - 'Tude, you up for that? Maybe DUG? Damn sure not me . . .
That's a tempting offer Ernie - wish I could have done it this summer like we had talked about. It's definitely high on the 2011 priority list. I want to do Long's Peak again as well, now that I've got a couple of Whitney trips under my belt, just to compare the two from a little more mature perspective - Long's didn't seem as hard a hike, but I recall it being dicier exposure - especially the Narrows and the Keyhole.