Sierra Storm Warnings Hit I-80 Friday, Where Trailers Always Need Chains

Four National Weather Service offices had winter storm warnings in effect for the Sierra Nevada on Thursday, November 12, every one of them opening Friday. The Sacramento office issued its warning at 12:05 a.m. PST and named the roads outright: snow above 6,000 feet across the Northern Sierra, including Highway 50, Interstate 80, State Route 4 and State Route 108, with total accumulations up to a foot, up to two feet at the highest peaks, and winds gusting as high as 60 mph. That warning runs from 10 a.m. Friday to 10 a.m. Saturday, and about two inches is possible as low as 5,000 feet.

The Reno office covers the Nevada side on the same clock: near 12 inches above 7,000 feet in the greater Lake Tahoe area, up to 20 inches along the crest west of the lake, ridge gusts of 70 to 90 mph and 35 to 45 mph through Truckee and the Tahoe communities. Its separate Mono County warning puts one to two feet above 7,000 feet with gusts of 45 to 55 mph along Highway 395. Hanford has up to 16 inches above 6,000 feet in the southern Sierra, from 4 p.m. Friday through 4 a.m. Tuesday. Las Vegas has five to 10 inches on the eastern Sierra slopes of Inyo County. Three of the four warnings say travel could be very difficult or impossible.

The transport angle

Donner Summit on I-80 is the whole story. It is the road a transcontinental enclosed load takes out of Northern California, which puts the San Francisco to New York corridor and the Monterey to New York run through a warning that starts Friday morning. US 50 over Echo Summit is the same problem on a narrower road.

Here is the part most owners do not know, and it is the reason a hauler behaves differently from a pickup truck in the same weather. Caltrans is blunt about towing in its own chain FAQ. Asked "Do I have to put on chains when I am towing a trailer?" the answer is "Yes, always." Asked "Even if I have 4-wheel drive?" the answer is "Yes." Under Requirement 1, the most common level posted, every vehicle towing a trailer needs chains on one drive axle, and a trailer with brakes needs chains on at least one axle of its own. There is no snow-tire exemption for heavy-duty commercial vehicles over 6,500 pounds. Caltrans goes further on this specific pass: whenever chain controls are posted over Donner Pass on Interstate 80, heavy trucks are usually required to carry link-type chain on at least the main drive axle.

Chains also set the clock. The speed limit where chains are required is 25 or 30 mph, which turns the climb and descent into a multi-hour crawl rather than a delay measured in minutes. Carriers in our broker network price that into a transit estimate when they see it coming, and the transit time guide explains how much a single mountain segment moves a cross-country delivery window.

The hard stop is screening. Caltrans may set up truck screening checkpoints at the approaches to major mountain highways, and when those are running, every heavy-duty truck has to stop and show personnel that the required chains are on board before it can proceed. Trucks without chains are turned back to a lower elevation, because there is no room to park at the top. A rig that arrives unprepared does not wait the storm out at the summit. It goes back down the hill with your car on the deck. Caltrans also notes that a highway is often closed outright before Requirement 3 gets posted, so a closure is the realistic worst case here, not an exotic one.

What to do about it

If you have a Friday or Saturday pickup or delivery anywhere between Sacramento, Truckee and Reno, call the broker today and ask two specific questions: is the assigned driver carrying chains for the drive axle and the trailer, and what is the alternate routing if Donner closes. The southern detour exists, but it is a long way around, and you want that number before Friday rather than after.

Move the appointment if the car is not time-critical. The Sacramento and Reno warnings expire Saturday morning and the passes clear fast once plows get ahead of it. Owners shipping on a seasonal calendar have the most room to slide a date, and the snowbird transport guide covers how much slack a winter booking should carry.

Do not let anyone load or unload on a snow-covered grade. A car with four inches of clearance on a slick incline is how a splitter gets destroyed, and a level, plowed commercial lot is a better handoff point than a mountain driveway. Ask what the enclosed desk will use as a dry alternate.

Check status before you call anyone to complain about a late driver. Caltrans runs the Highway Information Network at 800-427-7623, and QuickMap carries live chain control status by route.