With the National parks being so popular this time of year, and many of them only having a short season to repair the roads, you can always visit the NPS website and find the park[s] you are visiting for up to date info on conditions.
This summer there is quite a big construction program in Yellowstone.
Expect delays on the Mount Carmel highway between Zion and Bryce with day time closures and long diversions.
The Wawona Rd [41] to the Southern entrance of Yosemite has delays of up to 30 -60 mins.
In the Grand Tetons there are a few projects and you can expect up to 30 min delays on Teton park Rd near to Jenny lake.
Large vehicle [RV] alert. The Generals highway in Seqouia NP has expected delays of up to 1 hour and a new 22ft lenght restriction for the time being !!
Trail ridge Rd in RMNP is being worked on and could have combined delays along it's lenght of up to 1 hour.
Keep up to date with the goings on at the Grand canyon.
All links will update automatically so info may differ to that I posted today.
Anyone who has recently visited a park and can report any updates, please do !