Here are the preliminary numbers of total cars traveling to and through Idaho for the 2017 Solar Eclipse: Our traffic counters near the state borders counted 449,530 cars entering the state between August 18 and August 21. This number was an increase of 71,140 during that same time frame last year when 361,270 cars were counted entering Idaho at those same locations. ITD estimates more than 160,000 visitors came from out of state for the event (see methodology below).
The bulk of the visitors came from Utah and Oregon. Areas where the traffic was busiest include I-15 between Utah and Idaho Falls, US-93 near Craters of the Moon, US-20 near Arco, ID-95 from Payette to Riggins, and ID-55 north of Eagle.
Many locations in the mountains saw a steady stream of increased traffic throughout the weekend, up until the morning of the eclipse. Monday morning, routes along the I-15 corridor saw the biggest spike for day-of traffic. Travel home did cause congestion along the above routes. Most of that cleared up by 5:00 p.m. Monday, though congestion lingered on I-15 until 9:30 p.m.
ITD experienced an increase in visitors to our online resources, including the eclipse web page and blog posts. Total unique visitors to these pages is 82,000.
Traffic Counter Location†
2017 Eclipse Traffic‡
% Traffic Change
I-15, Pocatello (Exit 63)*
I-15, Dubois (near MT)*
I-15 Blackfoot (Exit 98)
I-84, W. of Caldwell (Ext 13)*
I-86, btw Twin Falls and American Falls (Exit 15)
ID-21, Robie Creek
ID-33, WY Border*
ID-75, N. of Shoshone
ID-75, N. of Hailey
US-20, NE of Ashton*
US-20, W. of Idaho Falls
US-20/26, E. of Arco
US-30, W. of Lava Hot Springs
US-91, UT Border*
US-93, Craters of the Moon
US-93, NV Border (S. Rogerson)*
US-95, N. of Salmon River Bridge*
* Site used to calculate out of state visitors
† For an interactive map of the traffic counter locations, click here.
‡ Counts ran from 11:00am 08/17/17 to Noon 08/21/17.
§ Counts ran from 11:00am 08/15/16 to Noon 08/19/16
This number is meant only to be an estimate of visitors to Idaho for the 2017 solar eclipse and is not intended to be authoritative. ITD’s method for estimating visitor numbers took the change in traffic count from 2016 to 2017 at border locations (marked with *), multiplied by 2.5 people per average vehicle, minus 5% for local traffic. This method does not capture the number of visitors who may have flown into Idaho via commercial flights or backcountry airstrips.
The Idaho Transportation Department is advising drivers who are planning to travel to view the eclipse to be prepared in the event of delays or an emergency.
The eclipse takes place on Monday, Aug. 21. It is anticipated there will be numerous travelers on highways and local routes.
Drivers should ensure their vehicles are in good working order. This includes getting the tire pressure checked, and making sure a vehicle’s battery, tires, headlights and brakes are in good working order.
In addition, drivers should carry emergency flares or portable signs to alert other drivers of an emergency, extra food and water, extra clothing or blankets for cooler weather, a flashlight with fully charged batteries, a fully charged cell phone and a map of Idaho highways.
The transportation department’s 511 web page and mobile app for Apple or Android will alert drivers to delays on the state’s highways. However, those planning to use the app on their smart phones or check web pages likely will not have cell service in remote or mountainous areas in Idaho.
When possible, travelers are encouraged to return home on Tuesday, Aug. 22, or later in the week. This will reduce the number of vehicles on highways that are returning home Monday afternoon.
The transportation department is working to develop a statewide plan to ensure motorists have the information they need ahead of the Aug. 21 event. ITD’s Jennifer Gonzalez shares some information about the agency’s preparation efforts, including how drivers can prepare, in the latest edition of the department’s In Motion video series below.
As the countdown to the August 21 solar eclipse approaches, the state of Idaho is gearing up for a potentially large influx of visitors that will be descending into southern Idaho to view this natural phenomenon.
In preparation for the event, the Idaho Transportation Department is working with other state and local agencies actively preparing and organizing a statewide plan, which includes being responsive, ready to assist law enforcement and most importantly, reducing impacts to travelers before, during and after the eclipse
“We know this will be a big draw for tourism in Idaho and most of the people are going to use our roads to get there and see it,” said ITD Chief Engineer Kimbol Allen. “We want visitors to have an enjoyable time in Idaho. We want to make sure that we do everything we can do have the roads open and ready to allow traffic to get in and back out after the eclipse.”
ITD is sharing tips with travelers on our website-as well as on overhead message boards and through the media that focus on safety, preparedness and travel plans. Most importantly, ITD encourages everyone to be patient, be responsible and give yourself enough time for travel prior to and after the eclipse.
We want our resources out informing people about what’s happening and what they can expect and what they can do about it and where the can be be, safely, to enjoy the eclipse.
The Idaho Department of Commerce has also devoted a statewide website with links to local planning resources, preparedness information and eclipse materials.