Crawlerway

The Crawlerway is a 130 ft wide double pathway at the Kennedy Space Center in Florida. It runs between the Vehicle Assembly Building and the two launch pads at Launch Complex 39. It has a length of 3.5 mi to Pad 39A and 4.2 mi to Pad 39B. A seven-foot (2 m) bed of stones lies beneath a layer of asphalt and a surface made of Tennessee river rocks.

The Crawlerway was designed to support the weight of a Saturn V rocket and payload, plus its Launch Umbilical Tower and Mobile Launch Platform, atop a Crawler-transporter during the Apollo Program. It was used from 1981–2011 to transport the lighter Space Shuttles to their launch pads.

Construction of the Crawlerway connected Merritt Island with the mainland, forming a peninsula. The main vehicle access road to and from the launch pads, the Saturn Causeway, runs alongside the crawlerway.

Construction
The crawlerway is composed of two 40 ft wide lanes, separated by a 50 ft median. The top layer is of Tennessee river gravel 4in thick on the straight sections and 8in thick on curves. Tennessee river rock was chosen due to its anti spark properties. Beneath that is 4 ft of graded, crushed stone, resting on two layers of fill. As of 2013 a project to repair and upgrade the crawlerway is in process, the first time since it was constructed that the foundation will be repaired. Additional rock has been added to the surface on June 2014.