Cameras and chain-control points on I-80. Each control point has a camera near it.
You have three ways to find out what a Sierra road is doing, and on a storm day they will not agree. Each is right about a different thing.
The roadside sign is the law
The illuminated sign at the control point, and the inspector standing next to it, decide whether you go through. Nothing on a screen overrides them.
If the sign says R-2 and every feed in the world says "no controls", the sign wins — it went up before anyone typed the update. What each level requires.
The feed is the record, and it lags
The Caltrans District 3 chain-control feed is what this site and every other one reads. It is accurate and it is official, but it is updated by people after the fact, so in a fast-moving storm it trails the sign by minutes to tens of minutes.
Where the feed beats the sign is trend. One sign tells you about one place. The feed tells you the control point moved from Castle Peak (7,247 ft) to Kingvale (6,069 ft) to Truckee (5,905 ft) over two hours. That says the snow level is dropping and the road is heading for a closure. The control-point ladder is what that trend runs down.
The camera is the ground truth, with caveats
A camera cannot tell you what is required. It can tell you what the pavement looks like, which is the thing neither of the other two describes.
- Stills refresh about once a minute, so a clear frame is up to a minute old
- Caltrans keeps the previous four images — use the strip, not the single frame, to tell weather from a dirty lens
- At night an unlit camera shows almost nothing; see Truckee to Reno at night
The trap: roadwork that reads as a closure
Caltrans counts lanes per direction, per work zone. A striping crew occupying both westbound lanes reports 2 of 2 lanes closed. A feed reader that treats "all lanes closed" as "road closed" then announces a shut highway while traffic moves past at 55 mph.
We hit this on 2026-09-14: three such records on I-80 on a clear morning, and the front page said "closure in effect". A record only closes a road here if it is typeOfClosure: "Full" on a Mainline facility. Everything else is reported as roadwork, with its location, its work and its end time.
So which do you trust
At the control point: the sign. Deciding whether to leave: the camera. Deciding whether it is getting worse: the feed, across several points. And the agencies are the authority for all of it — Caltrans, Nevada 511, and our own I-80 breakdown.