Looks good, it's all probably due to the spate of spring-like weather up there.
(It's scaring triple digits here, this last week, with heavy inversion domes to hold the humidity high, too--many complaints, but, this time last year we were into five weeks straight of 100+ )
Might be worth, on the next trip to Menards, to pick up a bag of sanded grout mix. That dry powder has excellent texture for ground work dry, and will "set" nicely using 50/50 water/PVA glue. A couple mounds along the track runs line wind-blown dirt might help with the present "float of the tracks. Or not.
As wide as theose tracks are, IRL, they would "float" over most firm surfaces--whether IRL is "good modeling" is a more personal choice.