The Atlantic City speedway was built in 1926 on a portion of the former Amatol site at a cost of millions of dollars. The project was backed and sponsored by Charles M. Schwab, Marshall R. Ward, H. E. Clark and S.D. Clark. The Jack Prince Construction Company of Oakland Ca. was the contractor. The track was a steeply banked 1.5 mile long and 50' wide oval. The board track was built to handle speeds of 160 MPH. The construction required 4.5 million board feet of lumber, enough to fill 253 railroad cars.
This wikipedia page has a few photos of board track racing:
http://en.wikipedia.org/wiki/Board_track_racing
http://venus.atlantic.edu/amatol/p-013_The_Development.html