Self-driving cars may be safe – but they could still prevent walkable, liveable communities

A self-driving car, driving itself. Image: Grendelkhan/Flickr/creative commons.

Almost exactly a decade ago, I was cycling in a bike lane when a car hit me from behind. Luckily, I suffered only a couple bruised ribs and some road rash. But ever since, I have felt my pulse rise when I hear a car coming up behind my bike.

As self-driving cars roll out, they’re already being billed as making me – and millions of American cyclists, pedestrians and vehicle passengers – safer.

As a driver and a cyclist, I initially welcomed the idea of self-driving cars that could detect nearby people and be programmed not to hit them, making the streets safer for everyone. Autonomous vehicles also seemed to provide attractive ways to use roads more efficiently and reduce the need for parking in our communities. People are certainly talking about how self-driving cars could help build more sustainable, livable, walkable and bikable communities.

But as an urban planner and transportation scholar who, like most people in my field, has paid close attention to the discussion around driverless cars, I have come to understand that autonomous vehicles will not complement modern urban planning goals of building people-centered communities. In fact, I think they’re mutually exclusive: we can have a world of safe, efficient, driverless cars, or we can have a world where people can walk, bike and take transit in high-quality, human-scaled communities.

Changing humans’ behavior

These days, with human-driven cars all over the place, I choose my riding routes and behavior carefully: I much prefer to ride on low-speed traffic, low-traffic roads, buffered bike lanes or off-street bike paths whenever possible, even if it means going substantially out of my way. That’s because I’m scared of what a human driver – through error, ignorance, inattention or even malice – might do to me on tougher roads.

But in a hypothetical future in which all cars are autonomous, maybe I’ll make different choices? So long as I’m confident self-driving cars will at least try to avoid killing me on my bike, I’ll take the most direct route to my destination, on roads that I consider much too dangerous to ride on today. I won’t need to worry about drivers because the technology will protect me.

Driverless cars will level the playing field: I’ll finally be able to ride where I am comfortable in a lane, rather than in the gutter – and pedal at a comfortable speed for myself rather than racing to keep up with, or get out of the way of, other riders or vehicles. I can even see riding with my kids on roads, instead of driving somewhere safe to ride like a park. (Of course, this is all still assuming driverless cars will eventually figure out how to avoid killing cyclists.)

To bikers and people interested in vibrant communities, this sounds great. I’m sure I won’t be the only cyclist who makes these choices. But that actually becomes a problem.

The tragedy of the commons

In the midsize midwestern college town I call home, estimates suggest about 4,000 people commute by bike. That might not sound like many, but consider the traffic backups that would result if even just a few hundred cyclists went out at rush hour and rode at leisurely speeds on the half-dozen arterial roads in my city.

Technology optimists might suggest that driverless cars will be able to pass cyclists more safely and efficiently. They might also be directed to use other roads that are less clogged, though that carries its own risks.

But what happens if it’s a lovely spring afternoon and all those 4,000 bike commuters are riding, in addition to a few thousand kids and teenagers running, riding or skating down my local roads? Some might even try to disrupt the flow of traffic by walking back and forth in the road or even just standing and texting, confident the cars will not hit them. It’s easy to see how good driverless cars will enable people to enjoy those previously terrifying streets, but it also demonstrates that safety for people and efficiency for cars can’t happen at the same time.


People versus cars

It’s not hard to imagine a situation where driverless cars can’t get anywhere efficiently – except late at night or early in the morning. That’s the sort of problem policy scholars enjoy working on, trying to engineer ways for people and technology to get along better.


One proposed solution would put cars and bicycles on different areas of the streets, or transform certain streets into “autonomous only” thoroughfares. But I question the logic of undertaking massive road-building projects when many cities today struggle to afford basic maintenance of their existing streets.

An alternative could be to simply make new rules governing how people should behave around autonomous vehicles. Similar rules exist already: Bikes aren’t allowed on most freeways, and jaywalking is illegal across most of the U.S.

Regulating people instead of cars would be cheaper than designing and building new streets. It would also help work around some of the technical problems of teaching driverless cars to avoid every possible danger – or even just learning to recognize bicycles in the first place.

However, telling people what they can and can’t do in the streets raises a key problem. In vibrant communities, roads are public property, which everyone can use for transportation, of course – but also for commerce, civil discourse and even civil disobedience. Most of the U.S., however, appears to have implicitly decided that streets are primarily for moving cars quickly from one place to another.

There might be an argument for driverless cars in rural areas, or for intercity travel, but in cities, if driverless cars merely replace human-driven vehicles, then communities won’t change much, or they may become even more car-dependent. If people choose to prioritise road safety over all other factors, that will shift how people use roads, sidewalks and other public ways. But then autonomous vehicles will never be particularly efficient or convenient.

The Conversation

Daniel Piatkowski, Assistant Professor of Community and Regional Planning, University of Nebraska-Lincoln

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

The IPPC report on the melting ice caps makes for terrifying reading

A Greeland iceberg, 2007. Image: Getty.

Earlier this year, the Intergovernmental Panel on Climate Change (IPCC) – the UN body responsible for communicating the science of climate breakdown – released its long-awaited Special Report on the Ocean and Cryosphere in a Changing Climate.

Based on almost 7,000 peer-reviewed research articles, the report is a cutting-edge crash course in how human-caused climate breakdown is changing our ice and oceans and what it means for humanity and the living planet. In a nutshell, the news isn’t good.

Cryosphere in decline

Most of us rarely come into contact with the cryosphere, but it is a critical part of our climate system. The term refers to the frozen parts of our planet – the great ice sheets of Greenland and Antarctica, the icebergs that break off and drift in the oceans, the glaciers on our high mountain ranges, our winter snow, the ice on lakes and the polar oceans, and the frozen ground in much of the Arctic landscape called permafrost.

The cryosphere is shrinking. Snow cover is reducing, glaciers and ice sheets are melting and permafrost is thawing. We’ve known this for most of my 25-year career, but the report highlights that melting is accelerating, with potentially disastrous consequences for humanity and marine and high mountain ecosystems.

At the moment, we’re on track to lose more than half of all the permafrost by the end of the century. Thousands of roads and buildings sit on this frozen soil – and their foundations are slowly transitioning to mud. Permafrost also stores almost twice the amount of carbon as is present in the atmosphere. While increased plant growth may be able to offset some of the release of carbon from newly thawed soils, much will be released to the atmosphere, significantly accelerating the pace of global heating.

Sea ice is declining rapidly, and an ice-free Arctic ocean will become a regular summer occurrence as things stand. Indigenous peoples who live in the Arctic are already having to change how they hunt and travel, and some coastal communities are already planning for relocation. Populations of seals, walruses, polar bears, whales and other mammals and sea birds who depend on the ice may crash if sea ice is regularly absent. And as water in its bright-white solid form is much more effective at reflecting heat from the sun, its rapid loss is also accelerating global heating.

Glaciers are also melting. If emissions continue on their current trajectory, smaller glaciers will shrink by more than 80 per cent by the end of the century. This retreat will place increasing strain on the hundreds of millions of people globally who rely on glaciers for water, agriculture, and power. Dangerous landslides, avalanches, rockfalls and floods will become increasingly normal in mountain areas.


Rising oceans, rising problems

All this melting ice means that sea levels are rising. While seas rose globally by around 15cm during the 20th century, they’re now rising more than twice as fast –- and this rate is accelerating.

Thanks to research from myself and others, we now better understand how Antarctica and Greenland’s ice sheets interact with the oceans. As a result, the latest report has upgraded its long-term estimates for how much sea level is expected to rise. Uncertainties still remain, but we’re headed for a rise of between 60 and 110cm by 2100.

Of course, sea level isn’t static. Intense rainfall and cyclones – themselves exacerbated by climate breakdown – can cause water to surge metres above the normal level. The IPCC’s report is very clear: these extreme storm surges we used to expect once per century will now be expected every year by mid-century. In addition to rapidly curbing emissions, we must invest millions to protect at-risk coastal and low-lying areas from flooding and loss of life.

Ocean ecosystems

Up to now, the ocean has taken up more than 90 per cent of the excess heat in the global climate system. Warming to date has already reduced the mixing between water layers and, as a consequence, has reduced the supply of oxygen and nutrients for marine life. By 2100 the ocean will take up five to seven times more heat than it has done in the past 50 years if we don’t change our emissions trajectory. Marine heatwaves are also projected to be more intense, last longer and occur 50 times more often. To top it off, the ocean is becoming more acidic as it continues to absorb a proportion of the carbon dioxide we emit.

Collectively, these pressures place marine life across the globe under unprecedented threat. Some species may move to new waters, but others less able to adapt will decline or even die out. This could cause major problems for communities that depend on local seafood. As it stands, coral reefs – beautiful ecosystems that support thousands of species – will be nearly totally wiped out by the end of the century.

Between the lines

While the document makes some striking statements, it is actually relatively conservative with its conclusions – perhaps because it had to be approved by the 195 nations that ratify the IPCC’s reports. Right now, I would expect that sea level rise and ice melt will occur faster than the report predicts. Ten years ago, I might have said the opposite. But the latest science is painting an increasingly grave picture for the future of our oceans and cryosphere – particularly if we carry on with “business as usual”.

The difference between 1.5°C and 2°C of heating is especially important for the icy poles, which warm much faster than the global average. At 1.5°C of warming, the probability of an ice-free September in the Arctic ocean is one in 100. But at 2°C, we’d expect to see this happening about one-third of the time. Rising sea levels, ocean warming and acidification, melting glaciers, and permafrost also will also happen faster – and with it, the risks to humanity and the living planet increase. It’s up to us and the leaders we choose to stem the rising tide of climate and ecological breakdown.

Mark Brandon, Professor of Polar Oceanography, The Open University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.