Cities: Skylines is easily my favorite city-builder of the past decade, but its expansions so far have been kind of lackluster. A big part of this is the fact that each expansion (so far) has had a pretty limited scope, meaning that I could really only recommend them if the expansion's particular theming was something that interested you.
While Mass Transit definitely has similarly tight theming, the effects of that theme are felt at a much broader level. Since Mass Transit seeks to specifically expand your transportation network (and fix some problems with creating transportation networks), and since every city of any size has a transportation network, this expansion has much more universal utility than any of the previous expansions.
Red light; green light
In fact, you'll likely start to see the impact of Mass Transit's new systems immediately upon loading up a city -- whether it's a new city or one of your established metropolises. If you're like me, then you'll immediately be thrilled to see that you can now name your streets. That's a cosmetic feature, but your budding young city will also soon encounter the new road and junction-management mechanics. You now have control over each and every intersection, and can assign STOP signs and traffic lights as you see fit.
As soon as I booted up the expansion, it informed me that it included a feature from my wishlist
Creating a main thoroughfare and want to make sure that traffic flows steadily through it? Assign it as a "priority road", which puts two-way stops on each road that intersects the thoroughfare, allowing traffic on the thoroughfare to move unobstructed.
Have a three-way (T) intersection? You can even assign only the "trunk" of the T to have a STOP sign, forcing traffic from that road to have to yield to traffic in the crossing road. Unfortunately, you can't add a median with a through lane.
You can force traffic to yield to major streets.
Even the tiniest of cities can benefit tremendously from this simple enhancement, and large metropolises can definitely see an improvement in traffic throughput with efficient use of priority roads. However, priority roads are really the only useful functionality of this feature. Since the game doesn't model car accidents (not even at an abstract level), there's kind of no point in creating four-way stops (as opposed to simply leaving the intersection without any stop signs at all).
This feature also usually entail some frustrating micro-management, as having to manually assign traffic lights and STOP signs can be tedious if you get stuck having to do it for every new intersection. There's also consistent issues with named roads not maintaining their names when I extend them, which forces me to have to manually extend the label onto the new road segment.
The much bigger benefit, however, is that managing traffic is made simpler by the addition of some new route overlays. Not only can you see how congested an individual road is, but you can also see which direction is most congested and also where all the traffic is coming from. This is another item from my wishlist. You can use this feature to see the sources of traffic driving on the selected road, and you can also use it on individual businesses and homes to see where the people at the home or business are coming from and going to. You can even click on an individual citizen or vehicle and see the route that it's currently following.
[LEFT] Every intersection caused congestion prior to the expansion. Since Mass Transit,
you can use "priority roads" [MIDDLE] to speed up traffic in major thoroughfares [RIGHT].
The wider, more open road
There's also some very handy new road types. There's some avenues with both bus lanes and decorative trees now, which is a small (but nice) change. There's also a new asymmetrical road that has a single lane going one direction and two lanes going the other direction. I've only found one or two use cases for this road, such as having slightly higher capacity going from industry to a nearby cargo station. It might also be useful for garbage collection and maybe for your leisure and/or tourism districts, but I've yet to find it necessary for either of those situations.
The much more useful item is the new highway types. Instead of a single, 3-lane highway and overpass, your highway options run the gamut from rural two-way highways, to double-lane highways, all the way up to behemoth 4-lane highways. I don't have to use one-way roads as highway bypasses anymore, as two-lane highways can now be used as bypasses to relieve excessive congestion.
Congestion can be relieved by upgrading to a 4-lane highway, and by building bypasses.
My agricultural and lumber districts can now also be connected by, cheaper, lower-capacity highways that help give my smaller towns a much more rustic and rural look. It's too bad that none of the new maps have their regions connected by these smaller, rural highways. There also still isn't a way to buy discontinuous plots of land, and connect them with highways or rail. I'd love to be able to build a more rural, spread out farming community, but the population thresholds and limited space usually force me into being more urban than I'd like. I guess I can always turn off the milestone system,
and have access to highways and all the plots of land right from the start.
O, Brave New World that has such vehicles in it!
As your city grows, it will also gain access to completely new forms of transit. Some of these are grounded in real-life transit systems, such as monorails, cable cars, and passenger ferries. There's also some more exotic and fantastical options such as the new airship commuter service. These features fall more firmly into the category of "take it or leave it" that has been the modus operandi of the Skylines expansions.
The game still doesn't allow you to build buildings without being adjacent to a road, but some of these transit options can allow you to neglect building road connections between distant and isolated regions of your city. Cable cars or blimps can take your citizens up a mountain to the observatory without having to build a road all the way down the mountain. Ferries can connect districts on different islands (or across a river) without the need for a bridge.
Passenger ferries connect districts on islands without the need for building a network of expensive bridges...
Of these options, the ferry is the only one that really feels like it fills a valuable or necessary role. A lot of the maps in this game have large bodies of water that separate land regions. Whether it be a river, or islands, crossing water is almost always something that you'll eventually have to do in this game. Considering the ubiquitousness of water on Skylines maps, it's quite surprising that the game went this long without having passenger ferries.
I had generally avoided island maps in the past because of all the wasted space, but with ferries, I find myself much more willing to try them out. I still end up getting frustrated by the game's generally poor interfaces for managing geographically-separated regions. Trying to make sure that each island has its own adequate amount of services (such as electricity, sewage, garbage, and access to cargo routes), and the inability to separately manage their budgets, is still a huge pain that usually stops me from enjoying such maps. In addition, if you are building on islands to access natural resources, you'll still probably need bridges to ship goods anyway, since the placement of cargo harbors is still absurdly restrictive. Same goes for passenger harbors. And there's also no boat police or firefighters to allow those services to extend across water.
... but asinine harbor connection rules mean bridges are still necessary if you want to connect island industry.
Ferries can also navigate the canals that were included in the free terraforming dlc. So even if you somehow manage to find a map that doesn't have navigable bodies of water, you can always make them, and then use ferries to navigate them. To this end, the Mass Transit expansion also has a new "wide canal" to give you enough room for your ferry traffic.
Creating ferry lines does seem a bit finicky. It's very picky about whether or not it's willing to go underneath certain bridges, and the game sometimes gave me an error saying that it couldn't find a path between two ports, even though they were connected. Don't be surprised if you have to tear down a bridge in order to make it tall enough for a ferry to travel below it (especially in the older maps). It would be nice if the game included some kind of UI to tell you if a bridge you're building is high enough to allow traffic underneath -- for both water and land traffic.
This is how ski lifts and ski resorts should have worked in Snowfall.
The other new transit options feel mostly superficial. There are a couple of new maps in this expansion (and in Natural Disasters) that have more hilly terrain, which makes the cable cars and airships at least somewhat necessary. These sorts of mountainous maps are exactly the kind of terrain that I was expecting from the Snowfall expansion, and the cable car mechanic even offers a possible framework for how ski lifts could have (and should have) worked. So once again, this expansion manages to make Snowfall look even worse in retrospect.
Oh, and there's also monorails, which are a more expensive upgrade to the trams that doesn't need to stop at intersections.
Managing your transit network
In addition to new vehicles, you'll also get some new UIs for your transit systems. There's a new widget that will break down how many passengers use a service at each stop, and which allows you to customize the number of vehicles assigned to a particular line.
You can view which transit stops are the most busy, and allocate the number of vehicles assigned to a specific line.
It's also a lot easier to combine different types of commuter services by utilizing the [very expensive and space-eating] new transit hubs. Remember the bus station that was added in After Dark? Well now, there's hubs that provide that functionality for other services (like a multi-platform train station), as well as combining them together into one mega-hub. Multiple bus lines can converge at a ferry port or monorail station to allow citizens to easily hop off one transit method and hop onto another.
Pointed back in the right direction
There are still some road types and transit infrastructure that I feel is missing, and which I need to go to mods to obtain. It would be nice to have a single mass transit hub that combines buses, metro, and trains. And, quite honestly: is a 12-platform train station really necessary? Could we get a 4-platform or 6-platform station first? Or maybe be able to build a single-platform train station and then add new platforms as the city grows and more train lines are added? (Hey, another useful application for modular buildings!) Same goes for metro stations, which still don't support multiple platforms at all... There's also still no three-lane, one way roads; nor are there any one-way roads with buss/taxi lanes or with bike lanes; nor can you create one-way roads that merge into another road rather than creating an intersection (for highway ramps, roundabouts, etc.).
That being said, Mass Transit actually provides useful tools for solving some of the actual problems that your growing cities are likely to experience. It's not some novel, optional content like After Dark or Snowfall, and it doesn't invent new problems for you to solve like Snowfall and Natural Disasters.
After getting off to a rocky start with its first two expansions, Colossal Order has really righted the ship of Cities Skylines by delivering excellent free content updates and with two solid expansions in Natural Disasters and now Mass Transit. While the new transit options feel a bit ho-hum (aside from the ferries), the new overlays really help to troubleshoot your city's existing traffic woes, and the new hub buildings and traffic management options give you some excellent new tools to help resolve those woes. While it doesn't feel quite as fresh or interesting as Natural Disasters, Mass Transit's sheer utility might make it the best expansion for Cities: Skylines to date.
Now I just have to hope a meteor doesn't rain down from the heavens and turn my beautiful monorail network into a smoldering crater...