Can you explain the I-5 Express Lanes in Seattle to me?

November 14, 2024 7:20 PM

How do the express lanes work on the 5 through Seattle? I can't find a concise explanation anywhere of where you can get in and where you can exit, and what are the rules (do you need a certain amount of people in the car? A transponder? Is there a toll?).

There's a map but it's hard to read if you're extremely stupid at understanding the express lanes, which I apparently am. What does it mean that almost all the exits seem to be marked as HOV? Where do they dump you out if you're driving solo, and is it significantly less good than the HOV exits? On the map it says the express lanes don't provide access to the 520 or the 90 but it sure LOOKS like they end just north of the 90, so...do they somehow prevent it? Or does it just mean they don't merge directly from the express lanes to the 90?

If you are a regular user of these lanes I would very much appreciate your tips, tricks, and personal anecdotes! I have many times yearned to enter them but I'm scared to because it's unclear to me how far south I have to drive before I can get off again. I have been burned before by Seattle "welcome to this thoroughfare! now stay on it FOREVAIRE" roads before and the allure of the express lanes is that they will make me go where I want to go faster. If I'm going to get on in Northlake and end up at Seatac before an exit manifests, I would obviously rather not get on.

Thank you, I feel extremely silly to be asking this question but it just seems like a BIG commitment to get on the express lane when it is so mysterious whether I'm allowed to use it or when I will be allowed to leave. What if you get on it and then it changes direction???? Halp

posted by potrzebie to Travel & Transportation around Seattle, WA (7 answers total)

The express lanes alternate between north and south during the day. IIRC they are southbound only until 10 am or so, and nb all other times until the early morning shift.
There are fewer exits and at least 1 is for transit only. they do not allow access to 520 or 90 because the onramps to those are from the main artery not the lower deck or center thruway.
they are great if you want to get off at 5th ave, but they are mostly to move traffic through the city not into the city.
You wont get trapped against traffic because they close it both ways and sweep before opening the other way.
posted by OHenryPacey at 7:43 PM on November 14 [2 favorites]

I know of entrances to the express lanes from downtown. These entrances are direction specific, so you can go north from Mercer and Cherry, for instance, but not south. Heading south, you get off downtown but not at Mercer. They are not HOV only, to my knowledge, but there are HOV lanes that are adjacent. Express lanes also change directionality depending on the time of day, running southbound traffic before 11am and then carrying northbound vehicles afterwards. If you don't know what exits you need or when you are traveling, then it is safer not to take express lanes and just budget more time for the regular lanes.
posted by They sucked his brains out! at 8:03 PM on November 14

The express lanes are a marvel of engineering: somehow they have been designed precisely so that they never go in the direction I want to go.

But seriously: they are your friend if you live in north Seattle and want to commute downtown or past downtown.

If you're not a carpool, there are only two downtown entrance/exit points; if you speed past those going south, you'll eventually rejoin the main I-5 south.

Even though the express lanes rejoin I-5 near I-90, they will not get you to I-90. At that part of the freeway, I-5 south has split into two pieces, only one of which connects to I-90... and that's not the one the express lanes dump you out into.
posted by qxntpqbbbqxl at 8:36 PM on November 14 [2 favorites]

The express lanes aren't tolled. The new tunnel, however, is. As far as I recall you'll get a bill in the mail for any tolls in WA state.
posted by fiercekitten at 9:55 PM on November 14

Best answer:

do you need a certain amount of people in the car?

There is no high-occupancy requirement for the express lanes themselves, but you need at least two people in the car to use HOV on- and off-ramps.

The HOV ramps are the ones in yellow on the WSDOT map: Downtown near Cherry/Columbia and Pike/Pine, and the on-ramp from NE Ravenna Boulevard. Wikipedia has a list of express lane ramps that might be easier to use than the map.

A transponder? Is there a toll?

No transponders, no tolls.

What if you get on it and then it changes direction????

They close the entrances and wait for the traffic to clear before the lanes change directions, so this can’t happen.

it's unclear to me how far south I have to drive before I can get off again

You can exit from the southbound express lanes at Mercer or Stewart. (If you are a carpool/HOV, you can also exit at 5th/Columbia or Pike.)

If you don’t exit downtown, you will merge onto the regular freeway. I believe your next chances to get off are at Exit 163B (6th Ave South in SODO) and Exit 163A (West Seattle Bridge / Columbian Way).
posted by mbrubeck at 9:55 PM on November 14 [1 favorite]

WSDOT has the basic details and a map if you're looking for just what you need to know.
posted by Aleyn at 8:38 PM on November 15 [1 favorite]

They're not a huge advantage most of the time, in my experience (which rarely involves driving during rush hour). I take them when I can but they're not worth driving in the wrong direction to find an entrance, or stressing out about getting over to the left lane.
posted by The corpse in the library at 7:04 AM on November 16