3 ms·

Why are roads an elastic demand but it seems that other transportation methods, like light rail, aren't? I've seen cases of quite a few expensive lines and rail

Why are roads an elastic demand but it seems that other transportation methods, like light rail, aren't? I've seen cases of quite a few expensive lines and rail-stops that have lower than expected utilization, but it seems like new highway roads and lanes get immediate use. Is it down to the fact that there is simply more "freedom" with regards to roads over rail?

pkulak 8y ago
People prefer to drive, so they do that first. Public transportation functions the exact same way, so long as there is no more road capacity. There are countless examples of new light rail stations spurring new development in the area.
baddox 8y ago
I think it’s because in the US cars effectively “won.” Even if mid and long distance passenger rail were more of a thing, you’ll have to rent a car at your destination anyway. In other words, with just a car you can get anywhere you want in the continental US in 2-3 days. With just passenger rail (or commercial air travel, etc.), you can get to passenger terminals in a lot of places, but that’s about it.
mklingen 8y ago
In areas where cities are dense enough for public transportaiton to make sense, adding a new line does indeed lead to induced demand. For cities that are spread out and unwalkable (read: almost all US cities), public transit isn't efficient enough to move enough people from point A to B, due to A and B being very far away -- never mind the fact that once you get to B, you can't even walk to many destinations due to the city being designed in such a sprawly, pedestrian hostile way. For public transportation to work, we first need to make our cities denser. The best way of doing this is by outlawing use-based zoning and moving to form-based zoning. That means getting rid of the concept of a "single family zone" and a "commercial zone", etc. and just specifying stuff about the materials and shapes of buildings. It also means outlawing parking minimums. Many cities around the world (and even a few in the US, re: Philadelphia, NYC) have this kind of zoning which allows for much denser development.
hannasanarion 8y ago
Are you factoring in network effects? I have lived in Phoenix and Tucson, where the light rail is a joke: they are so short and there's only one line, so you probably don't live close enough for them to be useful and they probably don't take you where you want to go. If there was more light rail, more people would use it, but since so few people use it, there is little incentive to grow the light rail. Contrast Hudson County, NJ, which has a light rail system that's used heavily, the trains are often full during rush hour. You can use it to get pretty much everywhere (except Union City and uptown Jersey City, which both require a long trudge up the Palisades).
yason 8y ago
Elastic demand requires free-flowing masses. I'm quite sure New Yorkers or Londoners would be able to fill as many new subway trains during the rush hour as you could humanly add to the rail network, at least on the sections that are most commonly shared between lines to different destinations. On the other hand, if the on-ramp of a highway would only let cars through for one minute every 10 minutes (which would be considered a good service interval for any suburban public transit), the demand for roadspace would likely be a bit less elastic. Ditto, if the highway would only go to a set of destinations with no connections. Motorists can embark on a trip any time, join the highway any time, and take any exit, and continue from there to local destinations. This free schedule suits way more people than fixed departures to fixed destinations using public transit. Only in a densely built city you can achieve the same: people sharing segments of public transit before diverging to a number of different destinations.
kodablah 8y ago
> Is it down to the fact that there is simply more "freedom" with regards to roads over rail? Yup. I live in a metro with the longest light rail system in the US (almost 100 miles) and I don't go anywhere near one during my commute and many don't. It doesn't get half the riders that the second-longest gets. I would not vote for light rail funding...different strokes and all that.

pkulak 8y ago

People prefer to drive, so they do that first. Public transportation functions the exact same way, so long as there is no more road capacity. There are countless examples of new light rail stations spurring new development in the area.

baddox 8y ago

I think it’s because in the US cars effectively “won.” Even if mid and long distance passenger rail were more of a thing, you’ll have to rent a car at your destination anyway. In other words, with just a car you can get anywhere you want in the continental US in 2-3 days. With just passenger rail (or commercial air travel, etc.), you can get to passenger terminals in a lot of places, but that’s about it.

mklingen 8y ago

In areas where cities are dense enough for public transportaiton to make sense, adding a new line does indeed lead to induced demand. For cities that are spread out and unwalkable (read: almost all US cities), public transit isn't efficient enough to move enough people from point A to B, due to A and B being very far away -- never mind the fact that once you get to B, you can't even walk to many destinations due to the city being designed in such a sprawly, pedestrian hostile way. For public transportation to work, we first need to make our cities denser. The best way of doing this is by outlawing use-based zoning and moving to form-based zoning. That means getting rid of the concept of a "single family zone" and a "commercial zone", etc. and just specifying stuff about the materials and shapes of buildings. It also means outlawing parking minimums. Many cities around the world (and even a few in the US, re: Philadelphia, NYC) have this kind of zoning which allows for much denser development.

hannasanarion 8y ago

Are you factoring in network effects? I have lived in Phoenix and Tucson, where the light rail is a joke: they are so short and there's only one line, so you probably don't live close enough for them to be useful and they probably don't take you where you want to go. If there was more light rail, more people would use it, but since so few people use it, there is little incentive to grow the light rail. Contrast Hudson County, NJ, which has a light rail system that's used heavily, the trains are often full during rush hour. You can use it to get pretty much everywhere (except Union City and uptown Jersey City, which both require a long trudge up the Palisades).

yason 8y ago

Elastic demand requires free-flowing masses. I'm quite sure New Yorkers or Londoners would be able to fill as many new subway trains during the rush hour as you could humanly add to the rail network, at least on the sections that are most commonly shared between lines to different destinations. On the other hand, if the on-ramp of a highway would only let cars through for one minute every 10 minutes (which would be considered a good service interval for any suburban public transit), the demand for roadspace would likely be a bit less elastic. Ditto, if the highway would only go to a set of destinations with no connections. Motorists can embark on a trip any time, join the highway any time, and take any exit, and continue from there to local destinations. This free schedule suits way more people than fixed departures to fixed destinations using public transit. Only in a densely built city you can achieve the same: people sharing segments of public transit before diverging to a number of different destinations.

kodablah 8y ago

> Is it down to the fact that there is simply more "freedom" with regards to roads over rail? Yup. I live in a metro with the longest light rail system in the US (almost 100 miles) and I don't go anywhere near one during my commute and many don't. It doesn't get half the riders that the second-longest gets. I would not vote for light rail funding...different strokes and all that.