As a road widening project is completed, traffic is alleviated for a short amount of time. Then as time passes word spreads, or more people move to the city, or kids get older and get their driver’s licences. More and more people know this widened road is the fastest route, so more people take it, thus undoing the improvement. Then the cycle starts again - either with the same road being widened again, or another one a block over, on and on until the world is covered in asphalt.
The solution is to make alternative transit more appealing than cars. Bikes and public transit already have significant financial benefits, but lack infrastructure to make it more viable in North America. Busses get stuck in traffic, bikes are forced to share lane space with cars or sidewalks with pedestrians.
How is alternative transit the solution? Cities that have public transportation still have traffic jams.
There was an English traffic engineer that predicted that avg speed in central London will always be like 9mph. No matter how many lanes or public transit options you add. If there is no traffic, people will take cars until traffic jams are unbearable to give up. Then the system finds equilibrium.
The key is public transit that doesn’t suck. For the last 100 years the car and oil/gas industries have spent billions of dollars undermining public transit.
Dedicated transit lanes, subways, light rail, protected bike lanes all make cars less appealing to those that want to use them.
Yeah, one of the best examples of this is the Vienna public transit network. About 1000 vehicles (bus, tram, light rail, subway) in service at rush hour, a daily total distance of over 200000km traveled, more year-long ticket owners than car owners in the city, and about 2 million “travels” per day, which is about 30% of all traveling done over the city (including pedestrian and bike traffic)
If that traffic would be routed only by car, the city would be a giant parking space; to compare, one subway train carries about 900 people in rush hour, which replaces 790 cars (avg 1,14 persons per car here). the subway interval in the rush hour is about 4 minutes. i live at one of the subway final destinations, which is on one of the far ends of the city - and i can be at the other side of town in about 25 minutes.
And constructing and running a public transit network is a pretty nice boost to the local economy, creates a whole lot of jobs. sounds like something a lot of us cities could make use of.
Mixed traffic works here, it allows mobility for all social classes (yearlong tickets cost 365€, so about 400$ incl. taxes), nearly all stations are barrier free.
The key is that both adding car lanes and adding alternatives like transit are subject to induced demand, but the consequences of it are different for transit than for cars. Not only is the limit of the added capacity much, much higher for a train than it is for a car lane, adding more traffic to the lane up to that limit makes the performance worse and worse (increasing congestion), while adding more transit ridership up to its limit makes the performance better and better (increasing train frequency and therefore reducing wait times).
Similarly, induced demand for walking and biking is a good thing because more people doing those things improves public health, doesn’t pollute like cars do, and takes up much less space.
So it’s not that induced demand is bad, it’s that inducing demand for cars, specifically is bad.
It’s called “Induced Demand”.
As a road widening project is completed, traffic is alleviated for a short amount of time. Then as time passes word spreads, or more people move to the city, or kids get older and get their driver’s licences. More and more people know this widened road is the fastest route, so more people take it, thus undoing the improvement. Then the cycle starts again - either with the same road being widened again, or another one a block over, on and on until the world is covered in asphalt.
The solution is to make alternative transit more appealing than cars. Bikes and public transit already have significant financial benefits, but lack infrastructure to make it more viable in North America. Busses get stuck in traffic, bikes are forced to share lane space with cars or sidewalks with pedestrians.
How is alternative transit the solution? Cities that have public transportation still have traffic jams.
There was an English traffic engineer that predicted that avg speed in central London will always be like 9mph. No matter how many lanes or public transit options you add. If there is no traffic, people will take cars until traffic jams are unbearable to give up. Then the system finds equilibrium.
The key is public transit that doesn’t suck. For the last 100 years the car and oil/gas industries have spent billions of dollars undermining public transit.
Dedicated transit lanes, subways, light rail, protected bike lanes all make cars less appealing to those that want to use them.
Yeah, one of the best examples of this is the Vienna public transit network. About 1000 vehicles (bus, tram, light rail, subway) in service at rush hour, a daily total distance of over 200000km traveled, more year-long ticket owners than car owners in the city, and about 2 million “travels” per day, which is about 30% of all traveling done over the city (including pedestrian and bike traffic)
If that traffic would be routed only by car, the city would be a giant parking space; to compare, one subway train carries about 900 people in rush hour, which replaces 790 cars (avg 1,14 persons per car here). the subway interval in the rush hour is about 4 minutes. i live at one of the subway final destinations, which is on one of the far ends of the city - and i can be at the other side of town in about 25 minutes.
And constructing and running a public transit network is a pretty nice boost to the local economy, creates a whole lot of jobs. sounds like something a lot of us cities could make use of.
Mixed traffic works here, it allows mobility for all social classes (yearlong tickets cost 365€, so about 400$ incl. taxes), nearly all stations are barrier free.
The key is that both adding car lanes and adding alternatives like transit are subject to induced demand, but the consequences of it are different for transit than for cars. Not only is the limit of the added capacity much, much higher for a train than it is for a car lane, adding more traffic to the lane up to that limit makes the performance worse and worse (increasing congestion), while adding more transit ridership up to its limit makes the performance better and better (increasing train frequency and therefore reducing wait times).
Similarly, induced demand for walking and biking is a good thing because more people doing those things improves public health, doesn’t pollute like cars do, and takes up much less space.
So it’s not that induced demand is bad, it’s that inducing demand for cars, specifically is bad.