"Grand Trunk Relocating on Detroit-Pontiac Line," Engineering News-Record October 27, 1932: 501-504. The source for most of the technical details on the relocation of the railroad tracks, circa 1930, plus specific information about Trowbridge Road Street Bridge.
Royal Oak Twigs and Acorns: A Book of History. Edited by David G. Penney and Lois A Lance. Little Acorn Press, Royal Oak, MI, 1996.
"Observer-Eccentric Newspapers," Birmingham, MI. various issues.
Image Sources
Royal Oak: The Early Years. Assembled by Owne A. Perkins. Golden Jubilee '71, Inc., Royal Oak, MI. 1971. (pictures of Woodward 1912 and pre-1930.)
Trowbridge Construction Picture -- "Grand Trunk Relocating on Detroit-Pontiac Line," Engineering News-Record October 27, 1932: 501.
Diagram of 1930 GTW Track Relocation -- "Grand Trunk Relocating on Detroit-Pontiac Line," Engineering News-Record October 27, 1932: 502.