This site is gorgeous. There is so much attention to detail. I don't quite understand the barely visible half curves right above the transport row for a particular explorer day.
I think the half curves just represent some form of travel. If you look at March 29th [1] there's a large curve for his 8 hour flight, and some small gray ones for walking to his gate
[1] http://aprilzero.com/explorer/march-2014/29/