That sounds fine. There are several 19th century versions of this in London, where a railway line was built next to or through a park [0]. Depending on the elevation, the park may continue underneath all the viaduct arches, or just some.
But, rail noise is considered much less annoying than road noise (British noise pollution regulations recognise this, and allow for more rail noise before sound barriers etc are required). I used to live on the 3rd floor overlooking a major line in London, and the students on that side of the building complained far less than the ones on the other side, overlooking a middle-sized road.
A highway is a different matter though. There will be fumes from pollution, and noise and vibration from vehicles. It's no wonder it's "affordable housing", no-one who can afford better will want to live there.
Zoom out a couple of steps from [1] and decide if you'd want to live next to a highway. Or, to a lesser extent, a railway with diesel trains, which have faint lines compared to many roads, but electric railways don't show up at all. (I can't find an equivalent map for Seattle.)
Interesting, I would have guessed trains were worst for noise but highways could be as bad if not worse. Maybe it's that people living next to highways is so common that we don't think twice about it.
In the richer parts of Europe, rails will be continuously welded and many or most trains will be electric.
Noise is obviously worse with diesel trains, although trains are so efficient that the engine will be idling a lot of the time. Poorly maintained clackety-clack track is probably more annoying, perhaps from vibrations more than sound.
I believe noise trains make is more regular than car and trucks accelerating discontinuously. And they come and go less than cars. Highways have this characteristic permanent low humming with permanent « wheezing ».
Right it varies all over the map. We lived on 'Triangle Place' which was a triangle because of the railroad tracks cutting across the neighborhood in a ditch behind the house. First night, 2AM, the train came through with that huge searchlight panning through the trees, then the steam horn "Waaaa, Waaaa, Wa, Waaaaaaa!"
We both sat up in bed like the dead rising, stiff as boards. After a moment I said "Oh, Train." She said "Oh." We lay back down and went instantly back to sleep.
Strange thing is, we never heard that train again. OR rather, it never woke us again. It went by every night for the next year that we lived there, but it never bothered us.
I woke up twice at night when I lived next to the railway in London.
The first time was at 06:01, when there was a deep rumbling. I assumed a freight train had stopped outside for some reason, and was now accelerating hard.
The second time was a short while later, when my bedroom smelled like a bus depot and the sky had turned purple.
Initially some of these crossings were scheduled to be run below ground but have been reconsidered due to cost.