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A reader writes: “The U.S. House [Transportation and Infrastructure Committee] came out with its pre-election transportation policy: The Moving Forward Framework, and access measures made it into what is otherwise a high-level policy document (with no hint about how they plan to pay for their wishlists.)”
On Access to Jobs:
It’s infrastructure investment that is smarter, safer, and made to last – with a framework that:
Ensures a transportation system that is green, affordable, reliable, efficient and provides access to jobs
Modernizes Project Planning – Requires States and MPOs to prioritize transportation access and to consider during the planning process all system users, job access, connections to housing, and creation of transportation options in underserved communities.
Revamps Existing Formula Programs
Amends core highway formula programs to prioritize investments and improve program implementation:
Fix it First – Prioritizes maintaining and improving existing infrastructure and bringing it up to a state of good repair, including roads, bridges, tunnels, and ferry systems.
On Road Pricing
Tackles Congestion Equitably – Institutes tighter standards around tolling and congestion pricing.
Tests the Viability of New Transportation User Fees
Transforms revenue collection and distribution by authorizing a multi-year national pilot program to test revenue collection to ensure the future viability and equity of surface transportation user fees, including a vehicle-miles travelled fee.
It’s almost as if it were written by a reader of this blog.
My friends at GoGet, an Australian CarSharing company, released the report “Let’s Fix Congestion!”. While I am allergic to the congestion framing, since obviously cities should be designed around accessibility, it is widely believed to be necessary to talk about congestion to get broader buy in from the media for any transport issue around here.
The strategy in the report is quite sound for a soundbyte: Remode, reprice, reshape. Quoting from the report:
Remoding is a strategy that shifts more people out of the dominant mode, the private vehicle, into other modes such as public transport, active transport, and shared mobility. This latter area includes on-demand sharing, an approach that can offer compelling convenience and affordability for the transport consumer.
We need to address the economic and taxation policies that have preferenced the private car over other transport modes, and in turn generate congestion.
Currently the true cost of using a private vehicle is kept from the consumer’s view, whether it involves not accurately pricing parking or congestion’s effect on productivity.
Our cities have been designed around the private vehicle, preferencing space for cars over space for people.
We need to re-imagine our built environments and associated land use policies. Density is not a bad word if it is density done right. Density done right means an abundance of local shops and services which encourage abundant local living. Local living encourages local transport, often active, public and shared, and disincentivises the private vehicle, particularly when combined with smart parking policies.
This slogan is of course is adapted from the environmental movement’s Reduce, Reuse, Recycle, part of the Waste Hierarchy. [Replace and Recover and sometimes added to this list.]
But did you know Franklin Delano Roosevelt’s New Deal strategy was “Relief, Recovery, and Reform”? The Three Rs have a long history.
A Sidewalk Talk Q&A with forward-looking transportist David Levinson.
It’s 2043. Few people in cities own cars anymore. It’s cheaper to rely on electric, self-driving taxis. Some vehicles are big enough to share; others are individually sized to make the most of limited street space. They have one button inside: Stop. Dynamic curbs—patrolled by enforcement droids—remain clear for deliveries, pick-ups, and drop-offs. Street parking no longer exists, and this space has been recaptured for better public uses.
That’s the future as seen by David Levinson, the University of Sydney transport professor who writes the popular Transportist blog and is co-author of the 2017 book The End of Traffic and the Future of Access. “Look back to the 1920s, and you have magazines that ask: What does the future look like?” he says. “Some of it is absurd. Why would we all be using blimps? But some of it’s still like: Why doesn’t the future look like that?”
The truth, he says, is that imagining tomorrow’s urban mobility raises far more questions than it answers. If we get used to the idea of using taxis, what other things will we no longer feel the need to own? What are the new things we now can do because robots can move around without supervision? What will we do with all the extra time we don’t have to spend driving? How do you allocate road space in a world with delivery drones?
“These things are unpredictable in how they play out,” says Levinson, who’s an advisor to the Sidewalk spinoff company Coord, which recently launched a data integration platform for urban mobility. Levinson spoke to Sidewalk Talk about the challenges facing cities today—and the innovations 25 years or so down the road.
You give a lot of thought to the future of transport. How do you see the biggest challenges facing urban mobility at this moment but also in the short- and longer-term future?
There’s the litany of automobile evils we all know: lack of safety, pollution, congestion, and so on. Those are all here and have been here for decades and will remain here for at least a little while longer. Trying to actually solve those collective set of problems, which can be done (a) through technology and (b) on the demand side, is the project for the next couple of decades.
On the technology side, the rollout of electric vehicles is relatively straightforward. The rollout of autonomous vehicles, which is more complicated technically, will probably be a little bit slower. There’s simultaneously the rollout of the transformation from an ownership model to a mixed model of fleet-owned vehicles. And along with this transition toward fleet vehicles there’s also the opportunity to right-size the automobile itself, so we don’t have these large, oversized vehicles holding only one person in them.
Moving towards the one-passenger vehicle has huge benefits, and that’s the biggest challenge we’re not recognizing. The electrification at this point is well understood. Only the oil industry has its head in the tar sands about that. On automation, people have an unreasonable expectation of how quickly we can deploy this kind of technology, but we’ve moved faster than I imagined we would. We’re getting to the point where we’re going to have passengers in cars where the only thing they have is a “Stop” button. And that’s great, but it’s going to take decades to fully deploy this, because such a big system has to be transformed. Remember a few decades after the mobile phone, and a full decade after the iPhone, just under half of homes still have a landline.
To get to a fleet of AVs with just a “Stop button” there’s so much data the car will need to have to make choices, or to offer you choices as a passenger. Do I take a toll road or free road? Do I get to stop here or not? Are streets classified in ways where maybe there’s surge pricing on some?
There has to be a real-time map of the environment at different scales: of the infrastructure, of the presence of other vehicles on that infrastructure. Then there’s a services layer that Coord is doing, a real-time map of road prices, curbside regulation and availability, and parking regulations and availability.
Then you have the question of the user’s value of time. How much are you willing to pay to save a minute, because Road X is more expensive but faster, and Road Y is less expensive but slower? That’s if you imagine we will have some kind of spatial differentiation—I’m not convinced we will. It might just be going toward a universal time-of-day pricing, where it’s higher at 4 pm than 2 pm, but it’s not higher on Road X than on Road Y.
Say on the freeway you’re charging more than on a local road per mile of travel because it’s faster. Then more people will use local roads, and that’s not what you want. But if you want more people using the freeways, are you going to charge a discount on the freeways? That’s counterintuitive. It’s going to look something more like a mileage charge with a time-of-day discount than a differentiation by route. That’s my sense of where this goes.
Would you say road pricing is fundamental to a better future of transportation?
It’s fundamental to a less time-wasting form of transportation. I think there’s significant gains to be had from automation and from refactoring the automobile. That is, if we can convince 90 percent of the trips that they can use a one-passenger car, we can double the capacity of roads just from splitting lanes. Then with automation we can double it again, because vehicles can travel closer to each other. That solves a lot of the problem in most places.
If you can double the capacity of the roadway, that alone buys you 40 years of population growth.
There’s a big question as to how curbs will be managed given the increased demand from new mobility services. Can that happen in the absence of road pricing?
I think curb management is very ad hoc right now. In big cities, this is a tension. Getting that data streamlined and making more rational policies has had no systematic thought given to it, Coord can improve the situation. There is a lobby for people who would be against on-street parking; that would be the people who own off-street parking. And there is the transformation towards shared vehicle fleets in cities; many fewer vehicles need to be stored on the road at any given time because most are in motion, and there are fewer vehicles around because they’re used more efficiently. So that opportunity to eliminate on-street parking and transform that space into bike lanes, bus lanes, and loading and unloading spaces is ripe, the time is right .
Information technology is making it so that we can track and enforce use of lanes in real-time with cameras. There are many ways this could play out. Maybe enforcement needs to identify vehicles by the license plate, which means the camera angle has to be right, which means cities might need a robotic Rita, meter maid. Every block could have its own little enforcement droid to make sure no one is violating the rules about parking their car too long or loading and unloading for longer than needed. And you can do all that without road pricing.
If we get rid of street-parking, do you envision the curb needing the same types of definitions it has now? This is clearly a loading zone. This is clearly a bike lane. Or could it be more flexible?
It could be more dynamic, for instance loading from 4 am to 6 am then it’s for movement from 6 am to 9 am then it goes back to loading. Something like a bike lane you’d want to make more permanent. And for a bus lane, when there are enough passengers to justify a bus lane, it should be a bus lane. You already have cities that have parking until 3 pm, then from 3-7 pm it’s a bus lane (called a ‘Clearway’ in Australia, New Zealand, and the UK). And they have at 3 pm a vehicle and crew making sure the street is clear and ticketing the vehicles that are there. It works well enough, though it is a bit labor intensive.
You can imagine once existing rules are in place and well documented with a systematic way of describing and mapping them, people can think more rationally about which of these parameters they want to adjust. Then it’s just exposing it, showing what the map looks like to someone on the local Curb Management Board, a new institution responsible for those regulations deciding how to maximize the value of curbspace for the community?
In this scenario, how would you envision pick-ups and drop-offs happening? Would they also be charged? Or they’d be directed to a certain place? I’m thinking of the scenario where you’re not driving, the car is driving.
Certainly they’d be directed to a certain place. You’d want to avoid loading and unloading them at an intersection. Maybe some midblock taxi stand equivalent. As part of your taxi license you get to pick-up and drop-off in whatever district you’re in, or maybe you pay on a per-drop-off basis. It depends how you’re collecting revenue from your taxi operators. In London, with the congestion charge, they exempted taxis arguing the price is embedded in the price of the license. That seems plausible if the license fee is large enough and you want people to use taxis instead of parking, then you want to encourage it and not put in another fee. And if you don’t unload at the designated place, that’s illegal and you get a fine, automatically assessed by camera or enforcement droid.
So how do we get to that place where we move away from the ownership model and toward the fleet model?
It’s a value proposition for the consumer. We already have taxi markets. But most residents say to themselves, it’s cheaper to own a car now than to get taxis every day. So if it costs $10,000 a year to own a car, that works out about $30 a day, and I’d pay more than that for my daily taxi, it’s cheaper for me to own a car. If the cost of taxis comes down to less than $30 a day, the value proposition says, I shouldn’t own.
Now there’s the out-of-pocket versus the fixed-cost question, but that can be dealt with through a subscription model. So just like my cell phone, and I have ‘unlimited’ data up to some threshold per month, I might have ‘unlimited’ rides up to some threshold per month, and then I go above that the taxi company charges me per ride.
The reason you should be able to get it under even $20 a day is that if you go toward automation and electric vehicles, the price of the vehicles should drop. Electric vehicles should be less expensive. To date they are not, but we’re moving in that direction pretty rapidly. Automation is the second thing. You’re saving on the cost of parking. That’s $30 a day alone in big cities. You’ve eliminated the driver so taxis are cheaper, so the marginal cost per ride is really low—cheaper than taxis are today.
But unless you can get that cost structure in place, people are not going to give up their car. And I don’t think public incentives are going to matter a lot here, because most cities won’t have the will or the money to subsidize shared rides just so there’s fewer private cars on the road.
So you see self-driving fleets that aren’t shared?
I see multiple models here. You have a taxi provider like Uber or Waymo providing what we would call a taxi service today, except it’s automated. You’ve got leased cars that are maintained centrally in some respects but you take them home with you, so you have them on-demand. Then you have privately owned cars, or less rigorous leases much more akin to today’s private cars.
In an urban area, I can have a car on-demand and some fleet manages it. In a remote area, a car on-demand is a 10-minute wait. Rural users are less likely to want a shared vehicle.
Do you have the same fear of the zombie or ghost vehicles—cars without any passengers in them?
There will be empty vehicles moving around in any case. There are passenger-less taxis moving around now. That’s probably on the order of 10-20 percent of distance. With a well-managed system, you get that down. With private cars, someone could say: I will drive into the city, then send it home to park, then have it pick me up in the afternoon. That would double miles traveled. That would be terrible. You’d need to have some sort of penalty for that. Road pricing becomes perfectly justified if that kind of behavior emerges.
What about the nightmare scenario where it circles the block for eight hours?
If people start doing that, road pricing is the obvious solution. But even without road pricing, you could make it a crime to circle the block more than once in a short period of time. You have road pricing by ticketing. If it’s automated with cameras, then it’s: we’ve identified your car on the same block three times in the past 15 minutes, that’s a $30 fine. People might complain a little bit, but cities will see that as a good way to disincentivize it, and they don’t have to go through the pain of implementing road pricing. Instead it’s a new crime, enforced using technology the way red-light running and speeding are now in some cities.
There’s going to be all sorts of new regulations. Teenagers will step in front of the automated vehicle to make it stop—we know this is going to happen. We will invent a set of laws and regulations, like ‘annoying a robot’, once these problems begin to emerge. Cities and counties are pretty quick at copying the regulations of adjacent jurisdictions. It’s a diffusion of innovation process. One place writes the rule, they get the rule right, then all the counties and cities around it just copy the rule.
Are there aspects of the future of transportation we’re not focusing on enough?
I think the curb space question is more generally the road space reallocation question. How do we recapture capacity we no longer need to move automobiles, and what do we do about it?
Doing the same thing better is the obvious first thing that happens. But what are the new things we can now do? It’s not just cars moving people. It’s person-less vehicles moving goods—and they’re not cars anymore. That’s going to change a lot about how we shop: what is the retail experience, what does it mean to want something?
Most discussions of shared AVs have an urban-centric viewpoint. How technology changes the world outside of cities is not well understood or much contemplated. It might be that the new transport’s impacts are less outside of cities.
The futurist’s job is to put trends together and paint scenarios, but in the end, we’re 25 years since the Mosaic web browser for the World Wide Web was released, and it has turned out different than was expected. Imagine in 1993 someone said: “Fake news being generated by Albanian teenagers for the purposes of getting ‘ad clicks’ on a social network called ‘Facebook’ from 60-year-olds would shape the outcome of the 2016 election and elect noted casino owner Donald Trump.” … This is not a scenario a futurist could have foreseen. 2043 could be very strange indeed.
This Sidewalk Talk has been edited for length and lightly for clarity.
So your city has traffic congestion. Welcome to the club. Congestion not only wastes time, it increases pollution and crashes. While this undoubtedly annoys you as a traveler, it could be worse; your city might not have congestion because no one wants to be there. Still, it would be great to have a thriving city without congestion. People could reach more destinations in less travel time, and thus have more time to spend doing the things they wanted. If you figure it out, let us know.
Political double-speak today “addresses congestion” rather than “solves congestion” (almost twice as often according to Google). This is probably because policy-makers want to sound like they are doing something without promising anything. But I don’t think talking to congestion accomplishes much.
There are a number of proffered solutions out there. Congestion is, in principle, a mostly solvable problem, even if no fast-growing city has fully solved it. This article outlines 21 ways that congestion could be solved. Some of these are dumb, many are good, one is great.
Capacity – Perhaps the most obvious, ‘common sense’, solution when demand (traffic) is in excess of supply is to expand capacity. This is what we do with most things if we can. If our house is too small, we make it bigger. If the internet is too slow, we add capacity. In roads, this usually means adding lanes to existing roads. The first problem with this solution is that it is expensive. Buildings are built close to (or on) the proposed expanded right-of-way, so taking them in addition to being costly brings in an additional socio-political dynamic — people don’t like to be moved. Further, if you expand capacity, demand will respond. Travelers will switch routes, time-of-day, mode, and destination to take advantage of the new faster travel times, which means these wider roads won’t be nearly as much faster as hoped for. New (induced) developments will be built, and much of the capacity will quickly be used up by new travelers. There will still likely be a small amount of travel time saved for existing travelers, and the new travelers do gain benefits (otherwise why would they make the trip), so it is not necessarily a bad thing, but it may not solve your congestion problem.
Connectivity – Often the problem is not width of the road, but where it goes. A new road that goes directly to the right place can replace a longer route that doesn’t. So reducing the circuity (indirectness) of the network through selected connections can reduce congestion and total traffic by taking traffic off of longer routes. Even when there is nominal connectivity, it might not be very good. A bridge can replace much slower and lower capacity ferries, eliminating a bottleneck. But as with capacity expansions above, it can be very expensive. In a mature network, all the cheap and useful roads have been built already. A new connection may be cheap, or it may be useful, but it won’t be both. The induced demand outcome also applies.
Closure – Perhaps counter-intuitively, if we shut down key links on the network, we could also reduce congestion. If people can’t get across a River, they won’t drive from Home to the River either, reducing traffic along that path. Just as there is induced demand when capacity is added, there is reduced demand when it is taken away. In selected cases there is something called Braess’ Paradox, which says that some links result in an increase in overall travel time when they are added (and so reduce overall travel time when they are closed) because individual selfish routing choices can lead to bad outcomes.
Controls – The next most obvious solution is to use the infrastructure we have better. When we have a stop-sign controlled intersection, and there are long queues, we add traffic lights, which manage traffic better because there is less time lost in starting and stopping. Coordinating traffic lights on a city street grid can make sure more vehicles hit green lights. The use of controls on freeways includes devices like ramp meters, the traffic lights at freeway on-ramps, that manage the input flow to keep the freeway flowing (more) freely (than it otherwise would). Traffic engineers have suites of controls that try to squeeze in a few more cars on the same set of pavement by reducing the size of gaps between vehicles. These can help, and may be worthwhile. However, this is on the order of a 10% reduction, rather than the 100% we would like to see. And these gains are potentially absorbed by both general traffic growth where that occurs, and induced demand in a mature system.
Crashes – It is sometimes estimated that half of all delay is due to non-recurring congestion, most notably crashes. First, we want people not to crash. Crashes can be reduced by better designed roads. Crashes can also be reduced with better-trained drivers. Making licensure more difficult so the drivers are better is one strategy. Making driving more expensive so fewer people (and especially fewer marginal drivers) are driving is also significant. More importantly, crashes can be reduced by better-designed drivers. Over the longer term, we need to replace the human with the machine. Second, we want crashes to be cleared quickly. Quick emergency response helps save injured travelers. Freeway service patrols (under various names), help clear crashes and reduce the amount of subsequent delay.
Construction – Maintaining roads is important, without proper maintenance they would eventually cease to be. But closing entire roads for construction can’t be the right strategy, can it? Well, it depends. The alternative, trying to do construction one lane at a time will take much longer. So for a 4 lane road, closing one lane at a time for 6 months each will take 2 years, but closing all 4 lanes, and requiring travelers to detour might take less than six months as it is more efficient. Doing all work at night or weekends is another strategy. The cost of the delays vs. the cost of construction need to be properly weighed.
Competing modes – Just as widening a road is in theory a solution to a congestion problem, building a competing mode is also a theoretical solution. By building a rapid transit line or running an express bus, or even building sidewalks and bike lanes, other people may switch off the road, leaving the roads faster for the rest of us. The traditional induced demand argument follows. The evidence on this is weak though, most transit construction serves transit riders (which is a good thing) and doesn’t reduce congestion much.
Gauge – Track gauge, the width of railroad tracks, determines the width of the trains. As with railroads, the gauge of roads has been largely determined, with freeway lanes being 12 feet wide, and cars, buses, and trucks are narrower so that they fit. Lanes on surface streets vary a bit more, but tend to be similarly sized in newer developments. Most cars carry one person most of the time, but are sized for at least 4, 2 in parallel, and 2 rows. If cars were half as wide, we could fit twice as many in the same space. This is what we do with motorcycles and bicycles. Pedestrians can even fit more. Before the motorcar, long distance travel by horse was one man / one horse usually, and the occasional horse and carriage for multi-person trips or cargo. Now the carriage is brought along whether it is needed or not, wasting space and delaying others. Redefining the gauge of road lanes, so that lanes at least are split for narrower cars could double capacity.
Storage – On surface streets, we waste pavement storing parked cars. A lane or turn-lane or half-lane or bike-lane or bus-lane can often be added in the space devoted to unmoving metal, increasing throughput. Adjacent property owners are often under the mistaken impression they or their customers have a right to park (for free!) on the public street in front of their house. When there is no congestion, this is not a problem. Where there is congestion, this artificial right is costly to society.
Information – People are terribly inefficient routers, choosing routes that are not only not the shortest for society (which is to be expected) but not the shortest for themselves either. Using real-time traveler information rather than their own intuition and incomplete mental maps, drivers can find the shortest path to their destination, reducing their trip length and travel time, and reducing congestion for others.
Autonomy– While humans can barely safely drive with a two-second following distance between vehicles, autonomous vehicles with advanced sensors, in an environment where most or all the cars are autonomous, are expected to follow at less than one-second. That doubles capacity right there. They also don’t require nearly as wide a lane as human drivers do, which could almost double capacity again (this is the same gain we would see with narrow cars). How well this work on city streets, as opposed to freeways, remains to be seen, but up to a four-fold increase in freeway vehicle capacity just from autonomous vehicles is well-within the realm of possibility, and while it will induce demand, should buy significant congestion reduction gains. Even non-freeways will benefit as more travelers switch to the less congested freeways.
The first set of strategies are basically supply side. But congestion is caused by a mismatch of supply and demand. So let’s turn to demand.
Locating – If only other people lived near where they worked (shopped, studied), they wouldn’t have to travel as far, and so would be on the roads less (assuming they still traveled by car) or not at all (if they walked). While at some level, people coordinate location of origin and destination (they are usually in the same metropolitan area), they could certainly do so better. From a public policy perspective, moving more jobs out to where people live, and more people to where the jobs are, increasing the local balance between jobs and housing can reduce travel. In practice this is difficult, as there is no mechanism to require people to take local jobs or firms to employ local residents. The best municipalities can do is ensure the zoning permits developers to build appropriate developments. Still, ensuring the opportunities are there is one thing (and at best you can ensure developers are permitted to develop these opportunities), ensuring people partake of those opportunities is another. The cost of this also needs to be considered. There are reasons many firms like to locate near other firms rather than workers, which has to do with economies of agglomeration and the efficiencies that can be had from close inter-firm coordination.
Telecommuting – At the extreme of mutually co-locating home with respect to work is working at home. This involves no commuting travel outside the home, though may induce some additional non-work travel outside the peak. This has been growing slowly over the past decades, and is amenable for many, but by no means most, jobs. Like location, this is largely an individual decision. Better broadband would help, and encouraging employers to allow or require employees to work from home would not reduce this trend, but it is hard to see outside of money or regulation in some form what persuades firms to behave differently with regards to incentives for where employees work. Still, the more people that tele-commute (tele-shop, etc.) the fewer that are traveling, all else equal, which it never is.
Scheduling – We also wouldn’t have congestion if not so many people wanted to travel at the same time. We could stagger work hours, so not everyone arrived at work at the same time. Some large firms already do this, but it could be expanded. The downside is that the whole point of everyone going to work at the same time is that they be there together (or at the same time as customers and vendors) so that can collaborate. The point of going to work is only in part the ability to use expensive machinery in isolation. It is also about the gains from cooperation of people being at the same place at the same time. If people didn’t need to do that, and were (almost) as efficient as working from home, then there would be little point in traveling at all.
Sequencing – We do not begin and end all trips at home, we chain our trips together to reduce the total amount of travel. We go from work to the store to another store to home. This not only saves us time, it reduces congestion. Do this more systematically, with a little more planning, and you can reduce more congestion.
Shipping – Just as chaining trips may be efficient for you, chaining trips may be good for your goods. Instead of you and your neighbor each making a trip to the store and back (A -> Store -> A, B -> Store -> B). The store can send out a truck (or robot, or drone) and drop off goods at you and your neighbor’s houses before returning (Store – A – B – Store), which should reduce the total mileage on the network (though the trucks will need to load and unload frequently).
Sharing – Carpooling has been around since the dawn of cars, and sharing the back of a horse, camel, or llama before that. It is easiest when there are two people going from the same place to the same place (like members of the same family going from home to work) at the same time. All this sameness though requires coordination to arrange, or sophisticated matching to discover. While people may carpool with non-co-resident coworkers in their youth, one party (whoever is the most efficient or earliest riser) will tend to find the cost of waiting for the ride (or worse, waiting for the passenger) to be too costly, and eventually everyone gets their own set of wheels if they can afford it. HOV lanes or restrictions in some cities encourage people to pickup strangers (sluggers or jockeys) to fill up the extra seats to save time. Overall this is a small phenomenon. But imagine you could get paid for picking someone up along the way and dropping them off — ridehailing services like LyftLine and UberPool are moving in this direction — you might be more inclined. Information technology is enabling everyone to be a taxi-driver. Whether they want to be is another question.
Sharing with Scale – Suppose instead of picking up one person, you picked up two, or four, or eight, or sixteen, or thirty-two. You became a jitney or vanpool or even a bus-driver. And if you pick up a lot of people, maybe that is more remunerative than the job you have, so you become a professional. And if you picked up thirty-two people along the way, you would want to be careful about the route so you don’t delay the passengers on board (your paying customers) too much. You have discovered the continuity between driving alone and public transit. And if someone else is driving a nice vehicle on a convenient route, maybe you forego the car and ride instead. You have helped reduce congestion. And if one vehicle is carrying thirty-two people who otherwise would have driven, we have removed thirty-one vehicles from the road. And if everyone were in a vehicle carrying thirty-two people, we can reduce congestion almost 97%. But for all the reasons identified above, this magnitude is unlikely. [The difference between this and competing modes above is that this sharing with scale emerged organically, while the other is a top-down investment in fixed route transit lines — process matters.]
Walking or Biking – Maybe you still like your independence and don’t want to comport to someone else’s schedule, you just don’t want to be in a car. If more people walked instead of driving, the sidewalk utilization rate would increase, while the road utilization rate would decrease. Bikes similarly would congest bike lanes and bike paths, but that’s not as much of a concern, and bikes in mixed traffic can sneak through without congesting cars that much. Walking and biking are both up over the past decade. The best opportunities for substitution are for short distances, which are a large share of trips though a much smaller share of miles.
Rationing – If your license plate ends in an odd number, you can travel Tuesday, Thursday, Saturday, and Sunday. If it ends in an even number you can travel Monday, Wednesday, Friday, and Sunday. Therefore each weekday will have half as many travelers, right? Alternatively, license plates ending in 1 or 2 can’t drive on Monday, 3 or 4 can’t drive on Tuesday, and so on. Therefore each weekday will have 20% fewer cars. This strategy has been tried in a number of cities, and has been used in the US to ration gasoline during the oil crises of the 1970s. In practice, people with money (which is to say, most people with cars) get a second car to travel when they want. People swap cars, or license plates. People get around these regulations, which are a terribly inefficient way to reduce congestion.
Pricing – Charging people for the use of roads, more when and where it is congested, less when and where it isn’t, will foremost reduce travel during congested times, and thereby reduce congestion, and may increase it in uncongested periods when there is excess capacity (depending on the charge) as people adjust their schedule. This better balances the load on the network, and is a strategy undertaken in most transport modes, as well as other time sensitive businesses like restaurants and movie theaters.
How do travelers reduce travel?This is the best part. Each individual decides for themselves when to change location, when to change schedule, when to work from home, when to have something delivered rather than making a trip to get it, when to use a different mode, when to share a ride, when to reroute, and when to forego a trip, thereby making decisions that are individually rational.
Doesn’t this lose road agencies money?This is the second best part. With pricing, properly regulated road utilities will see roads as a valuable commodity rather than a commons, and if they increase throughput more they can sell more. They will try to be more efficient about managing the use of the existing roadspace, but won’t have an incentive to build unnecessary new links.
Can this work?This is the third best part. There are many proposed strategies to implement pricing. Obviously this has been politically difficult, or it would already be widespread. Transforming road agencies into public road utilities is one step. Further, the emergence of electric vehicles and the advent of autonomous cars reopens the window of opportunity to consider pricing to replace gas taxes, and enable road demands be managed far more directly.
There are undoubtedly some pet solutions out there not discussed here, and lots of details overlooked. Feel free to add more in the comments.
The Road Pricing debate in the UK is much more advanced than the US. Many reports and white papers have advocated adopting road pricing to reduce congestion and pollution (though whether the fuel tax would be reduced is not quite clear, one suspects no). This has garnered some public debate, being shown on the national news and in the daily newspapers. The Telegraph has a link
to a petition at Number 10 Downing Street that opposes road pricing. To date 58,676 people have signed. I did not see a petition in favor of pricing. After the public comment, the government will make a decision, though I am doubtful the public comment will actually affect the decision.
While the success of the London Congestion Charging scheme are impressive, it is unclear whether the rest of the country is willing to go along with still higher prices to travel (fuel here is near the equivalent of $8.00 per gallon).