Kennewick, WA to Mercer Island, WA is 220.2 miles and takes about 4h 9m via US 97, US 12, and I 82, with a fuel budget near $49 and enough daylight to finish in a day. This trip stays within Washington state, beginning in the Pacific Coast region and ending in the same region. The drive is predominantly on major highways, making it a straightforward transit. It's a practical option if you need to get from point A to point B efficiently, with minimal fuss.
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
110.1 miles from Kennewick, WA
A natural place for your longest stop of the day
, about 2h 3m into the drive
.
Main Roads
Road
Distance
Duration
US 97
103 mi
1h 55m
US 12
70.9 mi
1h 17m
I 82
31 mi
33m
WA 240
11.6 mi
13m
North Fruitland Street
0.6 mi
1m
West Kennewick Avenue
0.5 mi
1m
West Columbia Drive
0.5 mi
1m
Southeast 36th Street
0.4 mi
1m
Longest stretch:
US 97
— 103 mi, about 1h 55m
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 Kennewick, WA and Mercer Island, WA.
1
Start on North Newport Street
0.1 mi·37 sec·North Newport Street
2
Turn left onto West Kennewick Avenue
0.5 mi·1 min·West Kennewick Avenue
3
Turn left onto North Fruitland Street
0.6 mi·1 min·North Fruitland Street
4
Turn left onto West Columbia Drive
0.5 mi·1 min·West Columbia Drive
5
Enter roundabout onto WA 240
0.1 mi·8 sec·WA 240
6
Continue on WA 240
6.4 mi·8 min·WA 240
Use the straight / slight right lanes.
7
Keep slight right at fork onto WA 240
5.1 mi·5 min·WA 240
Use the slight right lane.
8
Continue on I 182; US 12
0.1 mi·7 sec·I 182; US 12
9
Keep slight right at fork onto US 12
71 mi·1 hr 17 min·US 12
Toward I 82 West, US 12 West: Prosser, Yakima
10
Continue on I 82; US 97
31 mi·33 min·I 82; US 97
11
Keep slight left at fork onto US 97
103 mi·1 hr 55 min·US 97
Toward I 90 WestUse the straight / slight right lanes.
12
Take the exit
0.3 mi·45 sec
Exit 8Toward East Mercer WayUse the slight right lane.
13
Turn left onto East Mercer Way
332 ft·11 sec·East Mercer Way
14
Turn sharp right onto Southeast 36th Street
0.4 mi·1 min·Southeast 36th Street
15
Continue on Gallagher Hill Road
0.3 mi·43 sec·Gallagher Hill Road
16
Turn right onto Southeast 40th Street
0.3 mi·46 sec·Southeast 40th Street
17
Turn left onto 86th Avenue Southeast
0.3 mi·52 sec·86th Avenue Southeast
Use the left lane.
18
Turn left onto Southeast 42nd Street
0.1 mi·23 sec·Southeast 42nd Street
19
Arrive at destination
Southeast 42nd Street
Trip Plan
Given the 4-hour duration, leaving Kennewick in the morning is ideal, allowing you to arrive at Mercer Island with plenty of daylight. With only one recommended stop and a short drive time, flexibility is on your side. Keep an eye on your fuel gauge, especially during the 103-mile segment on US 97, as services might be more spaced out. The estimated fuel cost is $49, so plan accordingly and ensure you have enough for the entire trip before departing.
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 110.1 miles from Kennewick, WA, or about 2h 3m into the drive.
The longest continuous stretch on this route runs about 103 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 48 miles or 55m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 110.1 miles or 2h 3m 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 22m
Traffic, exits, and arrival timing usually matter more near Mercer Island, WA than in the middle of the route.
Before You Leave
+
Open the route before leaving Kennewick, 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 Kennewick, WA
This is one driving day of about 220.2 miles and 4h 9m.
Your first comfortable stop window is around 48 miles from Kennewick, 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 US 97 for about 103 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 14
5 decision points cluster between mile 8.3 and 219.9 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
6
8.3 mi into trip|~12m in|WA 240
Keep slight right at fork onto WA 240
Highway fork - watch signs carefully. Lane positioning matters here
Use the slight right lane.
6
13.5 mi into trip|~18m in|US 12
Keep slight right at fork onto US 12 toward I 82 West, US 12 West: Prosser, Yakima
Highway fork - watch signs carefully. Multiple destination signs - pick the right one
Toward I 82 West, US 12 West: Prosser, Yakima
7
115.5 mi into trip|~2h 9m in|US 97
Keep slight left at fork onto US 97 toward I 90 West
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
Toward I 90 West
7
218.5 mi into trip|~4h 5m in
Take the exit toward East Mercer Way
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the slight right lane.
Exit 8
Toward East Mercer Way
7
219.9 mi into trip|~4h 8m in|86th Avenue Southeast
Turn left onto 86th Avenue Southeast
Lane positioning matters here
Use the left lane.
Fuel & Cost
Regular Gas
$42.90 one way
$85.79 round trip
$4.95/gal25.4 MPG avg77 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$5.18
$44.94
$89.88
premium
$5.39
$46.74
$93.47
diesel
$4.80
$41.58
$83.16
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 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
66.1
0
$23.12
$10.57
Efficient EV
55.1
0
$19.27
$8.81
EV Truck/SUV
88.1
1
$30.83
$14.09
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
Kennewick, WA
Late night
in Kennewick on Monday
Local time
3:46 AM
PDT
Current temp
95°F
Sunny
W 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
Destination
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
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 cooler at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
4h 9m 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...
5 mi from route
~14 min detour
Free
near mile 220.2
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This is a predominantly highway drive, with 98% of the 220.2 miles on major roads. You'll experience a long stretch of 103 miles on US 97, likely offering a sense of open cruising. The transition to I 82 and then I-90 will bring more consistent traffic and potentially denser exits as you approach the Seattle metropolitan area. Expect minimal time on surface streets.
98% highway — fuel and pacing are the main things to plan.
19 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 103 mi on US 97.
How Hard Is This Drive?
6/10
This is a straightforward highway drive that stays mostly on US 97 and US 12. You will hit about 14 points where you need to pay attention to lane position or signs. The trickiest moment comes around 8.3 miles in near WA 240.
Driving Effort6/10
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 220.2 miles you will encounter 14 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 8.3 miles (WA 240): Highway fork - watch signs carefully. Lane positioning matters here; at 13.5 miles (US 12): Highway fork - watch signs carefully. Multiple destination signs - pick the right one; at 115.5 miles (US 97): Highway fork - watch signs carefully. Lane positioning matters here.
Elevation Profile
Gently rolling terrain
2,790 ft327 ft
Total Climb
2,942 ft
Total Descent
3,022 ft
Highest Point
2,790 ft
~173 mi in
Elevation Range
2,463 ft
Notable High Points
2,790 ft at ~173 miles+594 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 Kennewick, WA to Mercer Island, WA, road signs begin pointing toward Yakima along the way.
Kennewick is a city in Benton County along the Columbia River of Washington State, roughly between the Yakima and Snake Rivers on the south bank of the Columbia.
Kennewick is the largest of the Tri-Cities of Washington, which also includes Pasco and Richland. The Tri-Cities are the third most populous metropolitan area in the state, after Seattle-Tacoma and Spokane.
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.
Doable as a same-day drive at 4h 9m. Total distance: 220.2 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
4h 9m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (98%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 103 miles on US 97. The full list of main roads is in the Roads section above.
Yes — we found about 12 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.
It helps. This route has a higher-than-average number of complex decision points, which get harder in the dark. If the last hour of the trip is on surface roads or mountain grades, aim to arrive at Mercer Island, WA before sunset when you can. Check the Trip Plan for departure windows that land you in daylight.
Only with planning. This is a long drive for kids — consider splitting it into two days rather than pushing through. Plan at least 1 meaningful breaks. There are 12 rest areas along the route for bathroom stops.
The main spots that need attention: at 8.3 miles (WA 240): Highway fork - watch signs carefully. Lane positioning matters here; at 13.5 miles (US 12): Highway fork - watch signs carefully. Multiple destination signs - pick the right one; at 115.5 miles (US 97): Highway fork - watch signs carefully. Lane positioning matters here.
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 4.2 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 Mercer Island, WA, but most travelers stay overnight.
