I was part of the Track Art team for Forza 5, and it was a massive project where just about every piece was worked on by multiple people at multiple stages. I worked extensively on worldbuilding and under-the-hood work (splines, instance placement) for the Sebring prototype, plus a couple of generic trackside props, spent a month building collision mesh and splines for a drivable rough build of Monza (which was then iced / postponed until Forza 6), then did extensive work on roads and infield turf for Yas Marina (which had to be severely crunched down when the XBone turned out to be a little less beefy than what we were promised), and finally joined the all-hands-on-deck effort to prepare Prague for E3 (which involved a huge amount of instance placement, vegetation placement and deletion, and building content for entire zones which got cut due to perf issues before launch).