I have two transportation books for sale on amazon: NCEES sample questions for the transportation exam, and the Transportation Depth manual sold by PPI (same company that sells the CERM). Both are great books and have great karma 
my friend used them and passed on his first attempt!
http://www.amazon.com/gp/aag/main/ref=olp_merch_name_3?ie=UTF8&asin=1932613641&isAmazonFulfilled=0&seller=A1N1CE6UKHTLF4
my friend used them and passed on his first attempt!http://www.amazon.com/gp/aag/main/ref=olp_merch_name_3?ie=UTF8&asin=1932613641&isAmazonFulfilled=0&seller=A1N1CE6UKHTLF4
