We recently purchased the full electronic version of the HCM 2010. However, the electronic version does not come with a serial number as the hard copy apparently does. The electronic version costs the same as the hard copy, so I would think it would come with access to the full Volume 4, but it is not possible to sign up for access to volume 4 without a serial number. How does someone who purchased the electronic version access the full volume 4?

According to TRB, if you purchased a copy of the electronic version of the HCM and did not get a serial number, send an e-mail to Andi Kisiner (akisiner@nas.edu) to request a serial number. You will need to provide the details of your purchase.