As you sit in traffic on your way to work, you might find it hard to believe, but one day, that congested highway will be part of the mass-transit wave of the future. Instead of congested traffic, thousands of cars will be streaming down the lanes at 120km/h+, carrying tens of thousands of commuters to their destinations.
What is going to be the driving force behind this change? Automated driving. The wheels of change are moving rapidly. Google has successfully tested self-driving cars over hundreds of thousands of miles, and Nevada recently enacted new legislation explicitly making it legal for a self-driving car to drive on their roads.
But, aren’t cars inefficient? Don’t they take up a lot of room? Aren’t they expensive? No, actually, they may be one of the most efficient and effective transportation forms of the future. Let’s take a look at these objections:
A regular highway does not have that much capacity for the space it uses. Each lane can, in optimal conditions, move up to around 2,200 cars per hour. If you have 3 lanes per side, and 1.2 passengers per car, then that’s about 16,000 people per hour. And that’s under optimal conditions. If traffic gets too congested and slows to a crawl, far less people will be going anywhere, anytime soon.
One mass transit line has a similar amount of capacity. If you have 15 trains per hour in each direction, and each train carries 600 people, then you have a total capacity of around 18,000 people per hour. Mass transit also degrades with more traffic, so if you get more people per train you start to have problems with people taking time to embark and disembark at stations, doors getting jammed, etc… so even if you stuff more people in the trains, your capacity per hour does not necessarily go up.
Fully-automated driving has the potential to vastly improve on this state of affairs. Automated cars can network with each other and react instantaneously to changing conditions. A highway lane moving at 120km/h with a 16 meter (55 foot) spacing between cars has a capacity of 8,640 people per hour at the usual 1.2 people per vehicle. That is not a huge spacing, but it’s much more than a tailgater will give you. A fully automated highway with 3 lanes per side could carry 52,000 people per hour. This is a huge improvement; it’s like having a fully-loaded regular highway with 10 lanes on each side, with no accidents or congestion! As the technology improves and people get comfortable, speeds could be increased, increasing capacity even more.
When automated driving takes off, I also expect that more and more people will use the network like they use public transportation today, electing to use the vehicles as part of the network rather than owning their own car. These cars could be part of a mass personal transportation network, picking people up at their homes and dropping them off at their destinations. If you can double the average people per vehicle to 2.4, then your highway now carries more than 100,000 people per hour, and this also makes parking an easier problem to solve since the cars could drive themselves to cheap parking lots at the edges of cities, until needed again.
What about city streets?
Automated driving can also greatly improve the capacity of city streets, and it will be needed with all of that new traffic moving on the highways. Witness how traffic moves today: When you have a lot of traffic stopped at a red light, and the light turns green, it can take up to half a minute before cars at the back of the line even start to move. With automated driving, there would be no delay: every car would start moving at the exact same time. Red lights would be less necessary as cars could filter through gaps, weaving through the gaps in the cross traffic. If traffic is too heavy for that, then each side can still move a substantial amount of traffic.
Let’s say each road gets 50%, with 10% of that for left turning traffic. That’s still 45% for through traffic, and if you hit a 2/3rds second gap at 60 km/h, you get 2,430 vehicles an hour. A roadway with 3 lanes per direction and 1.2 people per vehicle moves 17,000 people per hour, and with 2.4 people per vehicle moves 34,000 people per hour.
Couldn’t people just drive much further than they do, negating much of these gains?
Sure, they could, but at some point you still need to pay the time cost of a long distance, since living 120 kilometers away will mean a long commute of an hour, even at high speeds. It would also be a lot easier to implement variable pricing on highways and roads. Instead of funding roadways through taxes, they could be funded through usage fees, whcih would help to allocate the traffic and resources much more effectively. Excessive demand would lead to high usage fees, which would spur additional construction or, at the very least, avoid subsidizing people who choose to live 50 kilometers away or more at the expense of those who live closer to the city.
Many to many is much more efficient in time
Public transportation planners often fail to consider how much time people actually need to take public transportation from one place to another. In most cities, public transportation can be significantly longer, up to two hours for a trip that might be 15 minutes in a car. Public transportation tends to be the most onerous for lower-income people that do not have high-paying jobs downtown and thus don’t benefit from the most efficient and effective public transportation routes. Sometimes I see public transportation as a massive subsidy for middle-income and rich people working downtown, as they do not bear the full cost of their transportation choice.
A massive personal transportation network would change this. Cars could pick you up right in front of your door, and drop you off at your destination. The system could be cost effective and affordable; since accidents will be less common, vehicle insurance will cost less, and since less time will be spent driving, gas and maintenance fees will be less. Intelligent combining of trips means that 6-8 people could share a ride in a comfortable van-type vehicle. A trip of 20 kilometers need only cost a couple of bucks or less per passenger, with no need for additional subsidization. The biggest savings will be in terms of time; those people who now suffer from hour-long rides will greatly benefit from having a lot more time available.
Public agency corruption
Mass transit is becoming more and more expensive, and cities everywhere are decrying a lack of funding. It costs hundreds of millions to billions of dollars to build new lines, and because mass transit corporations are usually taxpayer-funded public organizations, they not only hold a local market monopoly due to government privilege, but they also hold a gun to the local citizen’s head. If they don’t get the exorbitant compensation increases they feel they deserve, they can bring the city to a grinding halt.
The city I live in recently extended a subway line and constructed a few new stations at a total cost of nearly $1 billion, and even the transit agency itself estimates that only around 8,000 people use this new line. Most of those were also existing bus riders. Therefore, the government spent around $125,000 per passenger so that they could sit in a train in a dark tunnel for a few kilometers, instead of a bus.
Talk about a massive waste of resources! That money could have been spent elsewhere for a better return, or, better yet, could have been returned to the taxpayers. Keep in mind that maintenance costs for the tunnel, workers and trains also amount to another tens of millions per year. I wonder how many people pocketed out of that deal.
Mass transit is expensive
Building elevated rail or subterranean tunnels is very expensive and prone to significant cost overruns and corruption, as the government overpays and construction companies profit from mismanagement of public funds. Elevated rail also has the extra cost of “not in my backyard” protests and compensation.
At-grade rail is less expensive, but imposes significant penalties in the form of eminent domain evictions, grade-crossings, and slower transportation speeds. It is one of the worst ways of building a mass-transportation network, except where it is historical and a tourist attraction in places like San Francisco and Toronto.
Mass-transportation lines are also rigid. They cannot easily accommodate shifting patterns of demand. A grid network would be more flexible, but costs are usually so prohibitive that these are only built in places where they really make sense, like Manhattan.
Roads are cheap and accommodate flexible transportation patterns
Compare that against the cost of laying down concrete or asphalt. Concrete is a strong, durable and cost-effective building material, and once you lay it down, assuming it was built properly (I know, this is a stretch to assume in north america, but bear with me), it will last for decades without significant maintenance. As solar technology advances, roads may even be able to pay for themselves by generating electricity and selling it to the grid.
There is also a huge network of roads and streets already in place. There are environmental and political costs to building new roads, but in many places this is not actually needed. We just need to figure out how to use the existing network more efficiently and effectively, and make small local improvements where they make sense.
Most cities also have plenty of space for highway expansion without eminent domain — just look at a highway from above and look at how much space is unused; ditches, grassy medians, and large gaps between the highway and neighbouring roads and properties all add up to a lot of space that could be reclaimed, if necessary. Many cities don’t even bother landscaping this unused space or using it to build walls and berms which would reduce noise, which is a shame.
A final consideration is pollution. Do you really want to live near a highway or road with that much traffic? I think that this is a moot point. Cars are much, much, much less polluting than they were a few decades ago, and I fully expect that the pollution profile will drop to zero within a couple of decades from now. Quieter motors, less pollution and less congestion (and therefore honking) mean that city streets and highways should be more pleasant in the future, not less pleasant. Additional capacity means that more space can be allocated for bicycles for shorter distances, another mode of transportation which I think will be making a comeback and is already starting to in many cities.
Noise is still a valid concern; city traffic moving at 60km/h with quiet motors would make less noise than traffic today. Highways on the other hand, would be noisier since at those speeds, most of the noise comes from the wind and tires. As pollution drops, I say just cover these highways with plastic tubes. I’ve already seen this done in some cities around the world, and it can look beautiful if done right. The plastic tubes reduce noise to almost zero, without turning the highway into an dark and dreary tunnel, and without blocking views.
Subways will still have a place
In places like Manhattan, I think the subway will always have a significant presence. You can move a lot more traffic with automated driving, but there are just so many people there that subways still make a lot of sense. In most other cities, subways will be relegated to the ultra-dense core, and personal rapid transit will take over everywhere else. I think that where automated highways are going to make the biggest impact is in large, dense cities like Los Angeles. Contrary to popular perception, the metropolitan area of Los Angeles is relatively dense at 8,000 people per square mile, but because the city is so spread out and there are so many possible destinations, it’s almost impossible for a traditional public transit network to serve this type of city effectively. Places like this is where automated driving and a personal rapid transit system will make the largest impact.
The biggest losers will be the public monopolies that provide inferior service at an exorbitant price, and whose costs are inflating at double digits per year. Spending millions of dollars a year so I can sit in a dirty, smelly bus, and take two hours to get to my destination, while the rude bus driver gets paid more than me to drive a bus, and I am forced to subsidize that through my taxes? No thanks, and good riddance.
What are your thoughts? There will be a time where automated driving will have to mix with non-automated drivers, so it will likely be a couple of decades before most of the network is fully automated. The first candidates might be the most heavily congested highways, where 1 or 2 lanes can be opened up to fully automated driving.