The blue line indicates a very poor choice for a road location because this location provides limited access to the entire tract. This road would more than likely be placed in a low wet area of the tract, raising concerns over ponding and rutting issues. It may also be located within the SMZ. This location would probably have significant impacts on water quality.
The yellow line would also be a poor location for a road. It provides greater access to the tract, but it crosses the stream twice and also uses drainages as part of the road system. This location could certainly have significant impacts on water quality.
A road located along the green line has good access to the tract, while also limiting its impacts on water quality on the site. Notice that there is only 1 stream crossing, it stays along the ridge tops as much as possible, goes around the head of drains, and is placed at locations where the slopes are more gentle.