THIS MAP IS A WORK IN PROGRESS
Avenue is a CTF mixed with attack / defend where there is only one flag both teams are trying to get. To score, one team must take the intelligence from the middle of the map and bring it to the enemy base. When one team scores 3 points, they win.
Why is it called avenue? Probably because there's a road going through the middle of the map from one side to the other. Don't worry though, that pesky sightline will disappear as soon as someone grabs the intel.