Mercer Island, WA to Pasco, WA is 221.3 miles and takes about 4h 8m via East Channel Bridge, I 82, and US 97, with a fuel budget near $46 and enough daylight to finish in a day. This trip stays within Washington state, moving from the Pacific Coast region towards its interior. It's a manageable one-day drive, suitable for those looking for a straightforward transit between these two points. Expect a mix of driving conditions as you make your way east.
Trip Pace
Same-day drive is realistic
A same-day return is possible, but it will make for a full day on the road.
Break Rhythm
1 planned break
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
110.6 miles from Mercer Island, WA
A natural place for your longest stop of the day
, about 2h 5m into the drive
.
Main Roads
Road
Distance
Duration
East Channel Bridge
102 mi
1h 53m
I 82
64.1 mi
1h 8m
US 97
37.8 mi
42m
US 12
14.5 mi
15m
North 4th Avenue
0.6 mi
1m
Southeast 36th Street
0.4 mi
1m
Gallagher Hill Road
0.3 mi
<1m
Court Street
0.3 mi
<1m
Longest stretch:
East Channel Bridge
— 102 mi, about 1h 53m
Traffic on I-90
Hour-of-day weekday pattern from 125 FHWA count stations on your route.
Peak
3 PM
~2,533 veh/hr typical
· worst 3,340
Quietest
2 AM
~135 veh/hr
Peak-to-quiet ratio
18.8×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 52 weeks of 2023 FHWA Travel Monitoring Analysis System data. Weekday hours only (Mon–Fri).
Turn-by-Turn Driving Directions
Step-by-step road directions between Mercer Island, WA and Pasco, WA.
1
Start on Southeast 42nd Street
0.1 mi·27 sec·Southeast 42nd Street
2
At end of road, turn right onto 86th Avenue Southeast
0.3 mi·49 sec·86th Avenue Southeast
3
Turn right onto Southeast 40th Street
0.3 mi·43 sec·Southeast 40th Street
Use the straight / right lanes.
4
Turn left onto Gallagher Hill Road
0.3 mi·40 sec·Gallagher Hill Road
5
Continue on Southeast 36th Street
0.4 mi·1 min·Southeast 36th Street
6
Take the ramp
0.3 mi·46 sec
Toward I 90 East
7
Merge onto I 90
102 mi·1 hr 53 min·East Channel Bridge
Use the straight / slight right lanes.
8
Take the exit onto US 97
38 mi·42 min·US 97
Toward I 82 East, US 97 South: YakimaUse the straight / slight right lanes.
9
Keep slight left at fork onto I 82; US 12
64 mi·1 hr 8 min·I 82; US 12
10
Take the exit onto US 12
14 mi·15 min·US 12
Exit 102Toward I‑182 east, US 12 east: Richland, PascoUse the straight / slight right lanes.
11
Take the exit
0.2 mi·24 sec
Exit 13Toward North 4th Avenue: Pasco City CenterUse the straight / slight right lanes.
12
Turn straight onto North 4th Avenue
0.6 mi·1 min·North 4th Avenue
13
Turn right onto Court Street
0.3 mi·42 sec·Court Street
14
Turn left onto North 8th Avenue
0.1 mi·28 sec·North 8th Avenue
15
Arrive at destination
North 8th Avenue
Trip Plan
For this 4-hour drive, leaving in the morning is ideal to maximize daylight and allow for a relaxed pace. With only one recommended stop and a total duration under five hours, you have flexibility. Keep an eye on your fuel gauge, especially during the 102-mile stretch on the East Channel Bridge, as services might be more spaced out. Planning to depart Mercer Island early will ensure you arrive in Pasco with plenty of time to spare.
Morning Departure
An early start around 7-8 AM gets you there with plenty of daylight left.
Evening Departure
A late afternoon start means arriving after dark. Morning is better.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 110.6 miles from Mercer Island, WA, or about 2h 5m into the drive.
The longest continuous stretch on this route runs about 102 miles.
This is a comfortable same-day trip.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 49 miles or 57m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 110.6 miles or 2h 5m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 3h 23m
Traffic, exits, and arrival timing usually matter more near Pasco, WA than in the middle of the route.
Before You Leave
+
Open the route before leaving Mercer Island, WA so your first major turns are already loaded.
+
Leave with enough water and a charging cable within reach, not packed away.
+
Check your fuel range against the first long segment, especially if you are starting outside city service areas.
Day 1
Settle into the route from Mercer Island, WA
This is one driving day of about 221.3 miles and 4h 8m.
Your first comfortable stop window is around 49 miles from Mercer Island, WA.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 1 real break rather than only quick fuel stops.
The longest stretch is on East Channel Bridge for about 102 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Place data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 11
5 decision points cluster between mile 0.1 and 220.1 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
6
0.1 mi into trip|~0m in|86th Avenue Southeast
At end of road, turn right onto 86th Avenue Southeast
Complex interchange - multiple decisions in a short stretch
7
0.4 mi into trip|~1m in|Southeast 40th Street
Turn right onto Southeast 40th Street
Lane positioning matters here
Use the straight / right lanes.
7
103.7 mi into trip|~1h 58m in|US 97
Take the exit onto US 97 toward I 82 East, US 97 South: Yakima
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Toward I 82 East, US 97 South: Yakima
8
205.7 mi into trip|~3h 49m in|US 12
Take the exit onto US 12 toward I‑182 east, US 12 east: Richland, Pasco
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Exit 102
Toward I‑182 east, US 12 east: Richland, Pasco
7
220.1 mi into trip|~4h 5m in
Take the exit toward North 4th Avenue: Pasco City Center
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
Exit 13
Toward North 4th Avenue: Pasco City Center
Fuel & Cost
Regular Gas
$43.11 one way
$86.22 round trip
$4.95/gal25.4 MPG avg77 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$5.18
$45.17
$90.33
premium
$5.39
$46.97
$93.94
diesel
$4.80
$41.79
$83.57
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$43
Meals
$25–$50
Total
$68–$93
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 77.4 kg one way.
Prices: EIA weekly data, 2026-07-13.
Driving Electric?
About $23 in charging
· 0 stops
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
66.4
0
$23.24
$10.62
Efficient EV
55.3
0
$19.36
$8.85
EV Truck/SUV
88.5
1
$30.98
$14.16
Gas CO2
77 kg
EV CO2
26 kg (66% less)
Plan for 0 charging stops, roughly every 270 miles. Allow 25-40 minutes per stop at a DC fast charger.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Forecast as of Jul 18, 2026
Origin
Mercer Island, WA
Late night
in Mercer Island on Monday
Local time
3:46 AM
PDT
Current temp
77°F
Sunny
NW 5 mph0% chanceLive forecast
Red Flag Warning
Red Flag Warning issued July 18 at 11:42AM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Red Flag Warning
Red Flag Warning issued July 18 at 11:42AM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Destination
Pasco, WA
Late night
in Pasco on Monday
Local time
3:46 AM
PDT
Current temp
95°F
Sunny
SW 8 mph0% chanceLive forecast
Red Flag Warning
Red Flag Warning issued July 18 at 11:42AM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Red Flag Warning
Red Flag Warning issued July 18 at 11:42AM PDT until July 18 at 9:00PM PDT by NWS Spokane WA
Seasonal Notes
Summer travel usually means heavier construction, hotter rest stops, and busier weekend traffic around major cities.
Winter travel shortens daylight, so a route that looks manageable on paper can feel much longer after dark.
Holiday weekends tend to make both departure and arrival windows slower than the raw route time suggests.
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
18 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
4h 8m on the road
An early start around 7-8 AM gets you there with plenty of daylight left.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
National Parks Near This Route
Worth a detour if your schedule allows.
Klondike Gold Rush - Seattle Unit National Historical Park
National Historical Park
Seattle flourished during and after the Klondike Gold Rush. Merchants supplied people from around the world passing through this port city on their way to a remarkable adventure in the Yukon Territory...
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
You'll spend about 53% of the 221.3 miles on highways. The longest continuous stretch on a single road is 102 miles, which occurs on the East Channel Bridge. After the highway segments, the profile shifts to mixed highway and surface roads. Be prepared for the transition as you move from faster, more direct routes to potentially slower, more varied terrain.
53% highway, the rest on surface roads — varied driving throughout.
15 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 102 mi on East Channel Bridge.
How Hard Is This Drive?
5/10
This route mixes highway mileage with some local-road sections near the start or finish. You will hit about 11 points where you need to pay attention to lane position or signs. The trickiest moment comes around 0.1 miles in near 86th Avenue Southeast.
Driving Effort5/10
Moderate - straightforward overall, but long enough or busy enough to require pacing
Balances navigation complexity with total wheel time.
This drive requires moderate attention. Across 221.3 miles you will encounter 11 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
Where does it get tricky?
The main spots that need attention: at 0.1 miles (86th Avenue Southeast): Complex interchange - multiple decisions in a short stretch; at 0.4 miles (Southeast 40th Street): Lane positioning matters here; at 103.7 miles (US 97): Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Hilly terrain with moderate elevation changes
2,735 ft327 ft
Total Climb
3,293 ft
Total Descent
3,233 ft
Highest Point
2,735 ft
~47.4 mi in
Elevation Range
2,408 ft
Notable High Points
2,735 ft at ~47.4 miles+524 ft prominence
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
On the drive from Mercer Island, WA to Pasco, WA, road signs begin pointing toward I‑182 East along the way.
Mercer Island is a city in King County, Washington, consisting entirely of an island in Lake Washington. Once known as "East Seattle", it has become one of the region's most upscale residential communities.
Pasco is a city in the Columbia River Plateau in Washington State, roughly between the Yakima and Snake Rivers on the north bank of the Columbia.
Pasco is one of the Tri-Cities of Washington, which also includes Kennewick and Richland. The Tri-Cities are the third most populous metropolitan area in the state, after Seattle-Tacoma and Spokane.
Doable as a same-day drive at 4h 8m. Total distance: 221.3 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
4h 8m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (53%). Some complex stretches to watch for.
Scenic Drive
Mixed highway & surface route profile with national parks nearby.
Frequently Asked Questions
The longest stretch is about 102 miles on East Channel Bridge. The full list of main roads is in the Roads section above.
Yes — we found about 14 rest areas or service plazas within a short detour of the route (from OpenStreetMap). See the Rest Stops tab under Nearby Places for locations and mile markers. Plan to stretch, use the bathroom, and top off fluids every 2–3 hours on longer drives.
Yes, with realistic expectations. Build in a stop roughly every 2 hours, have snacks and activities ready, and check the Nearby Places tabs for kid-friendly stops along the way.
The main spots that need attention: at 0.1 miles (86th Avenue Southeast): Complex interchange - multiple decisions in a short stretch; at 0.4 miles (Southeast 40th Street): Lane positioning matters here; at 103.7 miles (US 97): Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — Klondike Gold Rush - Seattle Unit National Historical Park. See the National Parks section for detour distances and tips on detours.
Possible but tiring. At 4.1 hours each way, an in-and-out day trip would put you behind the wheel for 8.3 hours — manageable with a long break at Pasco, WA, but most travelers stay overnight.
