Demand almost never changes. Most bus routes are still virtually identical to the streetcar routes they replaced.

And the required infrastructure for light rail creates more demand for development along the line, as the rail itself signals more permanence to developers: they do not worry about it moving in a decade, like a bus route could.

The development demand is not a guarantee, and it can also come at the cost of destroying local businesses which cannot afford the downturn in customers during construction- many of which are small, minority owned sole proprietorships.

As for demand never changing... well, everything changes.

Source: Personal anecdata from living in an area where local government has been pushing more and more light rail development hard, in spite of never actually delivering any of the promised benefits to traffic congestion, ridership levels, community or business development.

I read somewhere that the real benefit of trams or light rail tend to come from the fact that they often come with a redesign of the traffic flows, right of way etc. Whilst busses are often stuck in the old traffic jam.

Bus rapid transit, of the sort you find in South America, has a lot of benefits of light rail without the initial startup cost of putting in rails for the reasons you describe: Dedicated rights of way, signal priority, and a lack of speed-killing sharp turns.

Bus rapid transit is a great compromise. They have special right of ways with dedicated signaling and lanes. But no need to lay rail so costs are much lower.

  They have special rights of way

... which come at the expense of taking away existing universal-use lanes, worsening all other traffic congestion.

Which then gets people on the bus, easing the congestion. This is a well documented effect, where the opposite happens, adding more lanes increases traffic. https://en.wikipedia.org/wiki/Induced_demand#Reduced_demand_...

  a well documented effect

Not really. Had the "road diet" actually resulted in a shift from cars to transit, the transit agencies would show a corresponding increase in their census and farebox return. They didn't.

Okay, you're right about the Wikipedia article not showing an increase in those statistics for mass transit. However, this paper does show a substitution effect for busses: http://clinlawell.dyson.cornell.edu/InTech_public_transit_ch...

However, there is an induced demand effect where because there are less cars, more people will drive. So in effect an extra lane appears, empty of the people riding the bus.

Short-term, that is correct.

But long-term the maintenance is significantly higher, as you need to replace the road surface very frequently.

A usual bus stop, or a BRT lane, has to be replaced every 6 months if it’s asphalt, and every 18 to 24 months if it’s cobblestone. That’s a significant expense.

While you can build and use light rail for decades.

What about concrete? US interstates can go decades with high truck traffic if they are concrete.

Pure concrete leads to significant shifts between the plates over the years, leading to the well-known bump every time you pass between plates. This obviously affects the bus’s suspension, and passengers, negatively.

Concrete with asphalt on top of it has the issue of the asphalt having to be replaced frequently.

I’m not sure if US interstates with concrete are different, but these were the only options discussed here in Germany.

Busses have higher operating costs per trip/mike/other measures, because there are way more drivers per rider vs rail. They’re obviously less expensive capital cost.

Every bus needs a driver and a vehicle with yet another powertrain. I'm not sure what energy consumption is like on a train but I suspect operating costs of all the buses is higher than a train that can cover longer distances. It seems to me a mix is the best solution.

Upfront costs for a train vs bus have to be orders-of-magnitude apart.

Obviously. My comment was about the operating costs.

Light rail will create demand to live near and locate businesses near the stations.

Can you name examples where this oft-predicted result has actually happened (in the USA, anyway)? That certainly hasn't been the result in the Bay Area.

It definitely happened in Portland when they ran the Orange line. We were house-hunting a year or two before the new light rail opened, and realtors showing houses along its route were already starting to make a point of mentioning it.

As soon as it actually opened, neighborhoods that could use it suddenly got a lot more desirable (read: expensive).

Bethesda, Maryland. It was very sleepy before it became a metro stop. In the last 30 years it had a crap ton of development mostly centered around the metro.

Actually... Can you name a few places in a metro area that didn't experience such a boom after a transit stop was introduced? In the bay area even? I feel like I have only ever seen examples of it being good for retail, restaurants, home values.

Metro considers itself traditional fixed rail, not light rail.

  a metro area that didn't experience such a boom

I was responding to the specific claim "Light rail will create demand to live near and locate businesses near the stations." The point isn't about whether a broad area benefits from rail (vs. no rail at all) but whether adding light rail to a fully built-out environment will drive more dense business development near the added rail and because of the addition of rail. I don't know of any USA data that supports that.

Ok. I thought you meant transit in general.

Take a ride from the Seattle airport to downtown on the light rail sometime, then. You will see a lot of nice looking apartments that didn't used to be there. And you will see some less nice neighborhoods interspersed.

Columbia City is a perfect example of this

This certainly happens very obviously in European cities. It’s possible that it happens less so in the US for cultural reasons, I suppose.

It's happening in advance of the Beltline transit in Atlanta. The Beltline has been building out park/trail and surrounding neighborhoods are doing very well. The light rail is currently just a promise.

Definitely didn’t happen in Houston. There was a spike of enthusiasm but light rail proximity has almost no effect on property values.

Is Houston's light rail actually useful? Last I knew it really only ran from one end of downtown to the other.

Houston is a bit too spread out. Where can you get to on the rail?

Denver. Lots of high density developments near the light rail and A line (technically commuter rail) stops.

Chicago and "El" train stops.

This is the claim used to advertise these, but do we really see many Amazonians commuting in from Beacon Hill or Georgetown?

I have seen this happen firsthand. It took a few years but the "rail line to nowhere" built near me around 5 years ago has giant housing complexes surrounding every station. It runs over capacity during rush hour now.

I assume this only happens in places where the roads are overloaded though

As I recall, Seattle zoning actually worked to prevent increased density and parking near transit stations.

In Seattle at least, I would expect the implicit suggestion to upzone near a light rail station would be at least as important as greater land value from demand. I'm not sure how much a light rail station induces Seattle to upzone -- I've heard mixed reports.