Here's a few of my suggestions. FYI to everyone, don't forget to use Street View!
I-90, Snoqualmie Pass and Vantage Bridge
https://www.google.com/maps/dir/47.3972 ... m2!4m1!3e0
I-90 goes very steeply up and back down Snoqualmie Pass. At the top of Snoqualmie Pass is a ski resort where I-90 curves in a horseshoe shape around it. Note that the west and east bound sections of I-90 splits into two separate roads near here as well. As you come down from Snoqualmie Pass you'll find the beautiful Keechelus Lake. Another thing to note is that there are numerous logging roads around Keechelus Lake.
From Cle Elum you are entering what we generally refer to as "Eastern Washington". This is where the state becomes vastly different from what most people think of Washington. It's mostly plains with lots of farm land.
https://www.google.com/maps/@47.0534786 ... 312!8i6656
The Thorp Fruit Mall is quite a prominent structure along the way, which is a popular grocery and antiques store. It's hard to miss. Perhaps a fun addition to add as roadside scenery.
https://www.google.com/maps/dir/46.9719 ... m2!4m1!3e0
From Ellensburg to the Vantage Bridge, the west and southbound lanes are split. Numerous windmills can be seen in this area. The Vantage Bridge crosses over the Columbia River, which is then immediately followed by I-90 curving sharply northward.
SR-14, also known as "Lewis and Clark Highway"
https://www.google.com/maps/dir/45.9440 ... m2!4m1!3e0
Mentioned above by @supersobes. Incredibly scenic route along the Columbia River. The approximate path of the Lewis and Clark Expedition went near/along this route so it has historical significance. For this reason it should definitely be included.
https://www.google.com/maps/dir/45.7207 ... m2!4m1!3e0
Pay close attention to the area near Drano Lake. There are a few tunnels built through the hills. A train track runs alongside SR-14 and crisscross over and under each other in this area.
US-101 and Forks
https://www.google.com/maps/dir/47.0716 ... m2!4m1!3e0
Loops around the Olympic National Park on the Olympic Peninsula. Scenic with lots of hills, forests and lake views. A fairly long section of it runs along the coast with great views of the Pacific Ocean. And perhaps as a fun easter egg, US-101 runs through Forks, which is known as the setting for the Twilight film series. Trust me, if you've ever been to Forks, the residence their will make you very aware of that fact. They're very proud of it, apparently.
I-82 and/or SR-821
https://www.google.com/maps/dir/46.9558 ... m2!4m1!3e0
https://www.google.com/maps/dir/46.9147 ... m2!4m1!3e0
Connects I-90 to SR-14. Honestly this route is very sparse but is a convenient way to get to SR-14. However SR-821 from Ellensburg to Yakima could be a very fun alternative as it is very twisty with beautiful hillside scenery.
Boeing Company and Paine Field in Everett!!!
https://www.google.com/maps/dir/47.9222 ... m2!4m1!3e0
This is obvious, but it wouldn't be right if Boeing in some form isn't included. The plant is MASSIVE when you drive past it. Now I wonder what fictional name SCS would use for Boeing.
Also, perhaps as a future addition to the Special Transport DLC: Wingspars! A fairly common sight on I-90 and I-405.
SODO, Boeing Field and Ports of Seattle and Tacoma
https://www.google.com/maps/@47.5713642 ... a=!3m1!1e3
This area in south Seattle is known as the SODO district, short for "South of the Kingdome" (which doesn't exist anymore
) and is the main industrial district and seaport of Seattle.https://www.google.com/maps/@47.5298204 ... a=!3m1!1e3
Boeing Field in the SODO district of Seattle should not be overlooked either. It is easily seen as you enter Seattle on I-5.
https://www.google.com/maps/@47.2555393 ... a=!3m1!1e3
Tacoma's seaport.
Evergreen Point Floating Bridge on SR-520
https://www.google.com/maps/@47.6404502 ... a=!3m1!1e3
It's the longest floating bridge in the world! That's more than enough of a reason to include it.
Tacoma Narrows Bridge and Bremerton Naval Yard
https://www.google.com/maps/@47.2697126 ... a=!3m1!1e3
The original Tacoma Narrows Bridge was infamous for swaying violently during strong winds which ultimately led to its collapse in 1940. Here's an iconic newsreel of the collapse which shows a car stuck on the bridge while it swayed:
Don't worry, the new one is of course much much stronger.
https://www.google.com/maps/dir/47.5256 ... m2!4m1!3e0
The Tacoma Narrows Bridge leads to Bremerton where the Puget Sound Naval Shipyard is. Dozens of decommissioned military ships are parked here. You used to see many WWII ships randomly parked in the middle of the Sinclair Inlet over a decade ago. The way SR-16 and SR-3 horseshoes around the Inlet gave a very clear view of all the ships parked there from every angle.
SR-17, SR-155 and Grand Coulee Dam
https://www.google.com/maps/dir/47.2959 ... m2!4m1!3e0
This one is my favorite routes! Starting from the small town of Ephrata, when you reach Soap Lake and follow SR-17 all the way north to the Grand Coulee Dam, you'll experience a canyon road that feels very much like those you'd find in the Southwest of the United States. There's a viewing area along this route for Dry Falls which is reminiscent of a miniature Grand Canyon. North on SR-155 gives an amazing view of Banks Lake on the left and high canyons on the right leading up to Steamboat Rock State Park which features a very prominent butte. Continue north on SR-155 and you'll reach the Grand Coulee Dam, which is the largest concrete structure ever built and one of the most powerful dams in the world. Needless to say, this is an incredibly scenic route that leads up to one of the most important man-made structures ever built so I hope SCS would consider adding this.
Aberdeen, Satsop Nuclear Power Plant and Kurt Cobain
https://www.google.com/maps/@46.9741083 ... a=!3m1!1e3
Aberdeen is one of the biggest logging towns in the region.
https://www.google.com/maps/@46.9604392 ... a=!3m1!1e3
https://www.google.com/maps/@46.9955728 ... 312!8i6656
As you're driving westbound on US-12 to Aberdeen from Elma, you can see the two cooling towers of Washington Nuclear Project 3 and 5 which is a former nuclear power plant.
https://www.google.com/maps/@46.9809526 ... 312!8i6656
Approaching Aberdeen, you are greeted by a sign that reads "Welcome to Aberdeen - Come As You Are", which is a reference to the song by grunge band Nirvana, in memory of Kurt Cobain who was born there.
PACCAR Technical Center and Kenworth factory
https://www.google.com/maps/@48.4663759 ... a=!3m1!1e3
SCS has already been there in person, so I don't need to remind them about this.
https://www.google.com/maps/@47.4932378 ... a=!3m1!1e3
One of Kenworth's biggest manufacturing plants is in Renton. Perhaps a good place for delivering parts in ATS.
Maryhill Loops Road
https://www.google.com/maps/place/Maryh ... 20.8035585
This is a completely random suggestion to be honest. The Maryhill Loops Road is a private road right next to SR-14. It is mainly used for racing events like rallying and drifting, but regardless I thought I would mention it anyway as it is a very fun road with great scenery.
