An electrophotography-based additive manufacturing system, comprising: a transfer belt traveling along a belt path around a series of rollers, wherein the rollers includes: a first moveable-position roller; a second moveable-position roller; and a plurality of fixed-position rollers; wherein a portion of the belt path from the first moveable position roller to the second moveable position roller is a fixed-velocity portion, and a portion of the belt path from the second moveable position roller to the first moveable position roller is a variable-velocity portion; a drive system positioned along the fixed-velocity portion of the belt path that drives the transfer belt in the fixed-velocity portion at a substantially constant belt velocity; an electrophotography engine (12s, 12p) positioned along the fixed-velocity portion of the belt path that deposits a part material layer onto the transfer belt; an image transfer assembly positioned along the variable-velocity portion of the belt path that transfers the part material layer onto a receiver medium; an image sensing system positioned along the belt path between the second moveable position roller and the image transfer assembly adapted to capture an image of the part material layer on the transfer belt; and a control system that: analyzes a captured image from the image sensing system to determine an in-track registration error between an intended position of the part material layer and an actual position of the part material layer; and adjusts the positions of the first and second moveable position rollers to adjust the velocity of the variable-velocity portion of the transfer belt thereby adjusting the position of the part material layer to compensate for the in-track registration error before the part material layer reaches the image transfer assembly. a transfer belt traveling along a belt path around a series of rollers, wherein the rollers includes: a first moveable-position roller; a second moveable-position roller; and a plurality of fixed-position rollers; wherein a portion of the belt path from the first moveable position roller to the second moveable position roller is a fixed-velocity portion, and a portion of the belt path from the second moveable position roller to the first moveable position roller is a variable-velocity portion; a first moveable-position roller; a second moveable-position roller; and a plurality of fixed-position rollers; wherein a portion of the belt path from the first moveable position roller to the second moveable position roller is a fixed-velocity portion, and a portion of the belt path from the second moveable position roller to the first moveable position roller is a variable-velocity portion; a drive system positioned along the fixed-velocity portion of the belt path that drives the transfer belt in the fixed-velocity portion at a substantially constant belt velocity; an electrophotography engine (12s, 12p) positioned along the fixed-velocity portion of the belt path that deposits a part material layer onto the transfer belt; an image transfer assembly positioned along the variable-velocity portion of the belt path that transfers the part material layer onto a receiver medium; an image sensing system positioned along the belt path between the second moveable position roller and the image transfer assembly adapted to capture an image of the part material layer on the transfer belt; and a control system that: analyzes a captured image from the image sensing system to determine an in-track registration error between an intended position of the part material layer and an actual position of the part material layer; and adjusts the positions of the first and second moveable position rollers to adjust the velocity of the variable-velocity portion of the transfer belt thereby adjusting the position of the part material layer to compensate for the in-track registration error before the part material layer reaches the image transfer assembly. analyzes a captured image from the image sensing system to determine an in-track registration error between an intended position of the part material layer and an actual position of the part material layer; and adjusts the positions of the first and second moveable position rollers to adjust the velocity of the variable-velocity portion of the transfer belt thereby adjusting the position of the part material layer to compensate for the in-track registration error before the part material layer reaches the image transfer assembly.