If you are curious as to what is going on up on Donner Summit, here is some information from Nevada County:

https://www.mynevadacounty.com/230/Donner-Pass-Road-Reconstruction

Over the next few months, there will be roadwork being performed on the Summit. The road will be closed from 7 a.m. to 5 p.m. Monday-Friday until October 15th! The site says that the road will be open to one way traffic on the weekends. The goal of this roadwork will be to widen the road to establish better bike lanes. They will also be enhancing parking pullouts and making improved areas for snow removal during the winter. Although this may currently be a pain if you are wanting to recreate on the summit, we are hoping this will be for the best in the long run. Please feel free to share your thoughts on this project in the comments!