I'll bet it's driven by a little old, gray haired, lady. The same one I get behind every time I'm on 2 lane road.
What gave it away, the left turn signal flashing? 
Blue hair and white knuckles.
Actually, rocks are quite on-topic when talking about the crawler. The path for the crawler is made with imported rocks from Alabama/Tennessee river beds. Allegedly there is less friction and less potential for sparks.
KSC Employee Update:
Overnight Success! Endeavour Glides Home, Atlantis Reaches Launch Pad
Space shuttle Endeavour sailed to Earth for the final time on Runway 15 at KSC's Shuttle Landing Facility overnight. Main gear touchdown was at 2:34:51 a.m., followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. This was the 24th night landing for the Space Shuttle Program.
On board were STS-134 Commander Mark Kelly, Pilot Greg H. Johnson, and Mission Specialists Mike Fincke, Drew Feustel, Greg Chamitoff and the European Space Agency's Roberto Vittori. The mission delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service.
STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Endeavour began its career in May 1992 and its accomplishments include embarking on the first servicing mission to NASA's Hubble Space Telescope and the first construction flight for the International Space Station.
To view Endeavour's final return to Earth, go to NASA's Video Gallery. Photos of landing will be posted throughout the day in KSC's Media Gallery.
Just before sunrise, space shuttle Atlantis is seen on Launch Pad 39A, where it will await the final launch of NASA's Space Shuttle Program.
Space shuttle Atlantis completed its final planned rollout from KSC's Vehicle Assembly Building to Launch Pad 39A overnight. The 3.4-mile trek began at 8:42 p.m. yesterday and wrapped up at 3:29 a.m. today.
The four-member STS-135 crew, along with thousands of employees, their families and friends, gathered to watch the historic journey. The milestone move paves the way for the STS-135 launch to the International Space Station, targeted for July 8.
STS-135 will be the 33rd flight of Atlantis, the 37th shuttle mission to the space station, and the 135th and final mission of NASA's Space Shuttle Program.
To view more photos of rollout, visit KSC's Media Gallery. Stay up-to-date on all the processing milestones of Atlantis at www.nasa.gov/shuttle.
And here's another cool pic of Endeavour's final launch with an F-15:
