Thursday, June 30, 2016

No Fourth of July travel charts this year, but we still have tools to help motorists navigate holiday traffic

By Barbara LaBoe

We know our holiday travel charts are popular. We love them as much as you do. Unfortunately, we weren't able to produce travel charts for this year's Independence Day holiday weekend.

Why don't we have the charts? There are a number of factors, but the bottom line is we don't have the data we need to confidently predict Independence Day travel this weekend. We know you rely on the travel charts, but we'd rather skip producing charts this one time than put out less-than-solid predictions that you use to make travel decisions.

Drivers headed across Snoqualmie Pass are likely to find backups due to heavy travel combined with construction-related lane reductions.

Here are some of the factors that went into this year's decision:
  • "Variable" day holidays – those that don't fall on the same day of the week every year – are harder to predict in general. There are far fewer Monday Independence Days, for example, to compare for historical background. For "standard" day holidays – Thanksgiving, Memorial Day, Labor Day – the predictions are easier (and more accurate) because we have year to year data. We will have Labor Day charts again this year. (For midweek variable holidays we don't produce charts because traffic is less heavy those years and it's hard to predict when or if people will travel mid-week).
  • Historical challenges. The last time Independence Day was on a Monday was 2011, during the height of the recession with tight budgets and soaring gas prices. People didn't travel as much, so traffic predictions based on that year aren't as helpful. The previous Monday Independence Day was in 2005. A lot has changed since 2005, which makes those numbers less than ideal for predictions.  
  • Holidays aren't interchangeable. Travel is different depending on the specific holiday as well as the day of the week/weekend the holiday falls. If a holiday and fireworks are on a Saturday, for example, Friday traffic will be different than if that same holiday is on a Monday. So, while previous holiday predictions might give a general, overall idea of travel, the hour-by-hour predictions from other holidays can't be easily swapped in and out.

I-90 through Ellensburg is expected to be one of our most congested areas during Independence Day weekend.

While we use historical and current traffic numbers in the analysis, our holiday predictions also are as much an art as a science. Analysts consider several factors – was there bad weather or a crash that delayed traffic; are certain holiday events on a specific day expected to alter driving patterns; is there a significant construction project that will add to congestion, or cause people to delay or detour? This year's multiple construction projects on Interstate 90 (see below), for example, would have presented quite a challenge in making predictions. After each year they also compare how their predictions panned out, and make adjustments from there.

What to expect in the future
We've already started working on changes to our templates and analysis that will make variable day holiday traffic easier to predict going forward, but with that work still in progress, we were not able provide specific hour-by-hour predictions for the Fourth of July.

What we can predict
Though we don't have hour-by-hour predictions, it's safe to say traffic volumes Friday afternoon and evening are likely to be heavy as people head out for their weekend. Likewise, drivers on the roads Monday afternoon and early evening should expect heavy holiday traffic. Use the travel information below to help you 'know before you go' this holiday weekend!

Our ferries carry a huge amount of traffic during Independence Day. Be sure to make reservations or walk-on if possible.

The Fourth is expected to be the busiest weekend of the year for Washington State Ferries. Extra sailings will be added for several routes. Reservations are strongly recommended for the San Juan Islands, Sidney, BC or Port Townsend/Coupeville. Travelers can also consult the best times to travel tab on the right of each route's summer schedule listing. If possible, it's always a good idea – and will save you long waits – if you can walk on.

Allow extra time for Interstate 90 travel
Travel across I-90 from the summit of Snoqualmie Pass to Vantage (pdf 742 kb) is going to be particularly tricky this summer – including the holiday – due to a number of projects that will ultimately improve travel for everyone.
With lane closures for an ongoing bridge painting project,
the Vantage Bridge will see significant congestion during
Independence Day weekend, so if possible leave
early or late in the day.

A particularly tough spot is the Vantage Bridge, which is down to a single eastbound lane until the end of summer due to a bridge painting job (painting a bridge extends its life by preventing rust). Work won't take place during the holiday, but the heavy concrete barriers can't be easily removed and a work zone has to stay in place in case of high-wind emergencies, so the single lane of eastbound traffic will remain. Plan on lots of extra time to get through this area.

Other spots of construction and delays include:
  • The Summit of Snoqualmie Pass east near Keechelus Lake (mileposts 54-62)
  • Easton area (mileposts 67-70)
  • Ellensburg area (mileposts 106-122)
  • US 2 in the Gold Bar/Sultan area

Prepare now for holiday traffic
Across the state, drivers can:
  • Get informed about WSDOT's online tools, including mobile apps, traffic cameras and email alerts.
  • Visit our online traveler information about traffic, weather and ferry schedules; call 5-1-1 for updated road conditions.
  • Follow WSDOT's social media accounts, such as Twitter and Facebook.
  • Pre-program your vehicle radio to 530 AM and 1610 AM for highway advisory radio alerts.
  • Leave extra time for travel; don't rush and be extra alert: one crash can snarl traffic for hundreds of drivers.