They only do this on the weekends which is rather ironic as that is when the traffic is the worst.
If you are coming into Yosemite Valley on a Saturday after 11 AM in the summer, I would recommend parking somewhere before the Four Mile Trail Head and then walk to the bus stop at The Four Mile Trail Head (God be Praised that the bus now goes all the way out to that trailhead saving several miles of road walking post-hike). Take the bus in the rest of the way. Traffic is a nightmare.
I never thought I would say this but the Valley needs a traffic light at the intersection of Northside Dr. and the Village Parking Lot/Village Dr. The congestion there is due to major uncontrolled pedestrian movement at all four crosswalks. There is a shuttle bus stop right there just to make matter worse. The problem here is that it is so chaotic that it is only a matter of time before someone gets injured and a VERY STRONG case could be made against the NATIONAL PARK SERVICE for not taking steps to monitor this situation. A traffic light would not only aid the car congestion but make things much safer for pedestrians.
PS....If I remember correctly, I think they do post a Ranger at that intersection on the weekend to direct traffic. But the mere fact that a Ranger needs to be stationed there just shows that the Park Service is already aware of this problem spot.
PPS....if you only have one day to spend in the Valley please do not go on a Saturday.....it is not worth it. There are far more fun things to do than to sit in a hot car.
