I have 2 big and 2 medium trips planned for 2018 so far:
Early January (medium): to DC for TRB. Main purpose is the TRB Annual Meeting, so only a short portion of the trip will be roads. Pretty direct route down (though I plan to clinch NJ I-295 and a couple things in MD), but heading back, I'll be doing a lot of detouring to clinch in the Baltimore area and Delmarva. Visiting a couple museums in Baltimore and I should be able to finish Maryland's Interstates (only missing a few things right now). May do some more foot-clinching in DC proper if weather cooperates. I actually have a decent amount of DC's US routes clinched on foot right now.
Spring Break (March, big): Shreveport for the meet. Ton of new mileage here and I'll be combining this with one of my other passions (hiking), as I'll be visiting 7 state high points on the way down and back. 5 new states planned (MS, AR, OK, TX, FL) and I intend to clinch US 13 on the way home, including my first trip over the CBBT.
Late April (medium): Central PA for the meet. Will be taking a circuitous route out so I can visit the 5 PA counties I'm missing, will probably spend the day after the meet hiking at Ricketts Glen if weather cooperates.
August (big): cross-country trip. It will be my first time visiting MO, KS, CO, UT, AZ, NV, CA, OR, WA, ID, MT, WY, SD and I will clinch I-70 and I-90, along with California SR 1 north of San Francisco and some of the fun roads around Zion, Rainier, and Glacier NPs and in the Black Hills. Ton of hiking and I plan to visit the KS, SD, and IA high points