Birmingham is considering a 20mph speed limit in the southern half of the city. Will it work?

Those were the days: a traffic policeman in Birmingham in 1926. Image: Hulton Archive/Getty.

Birmingham City Council, the largest local authority in Europe, has announced proposals to implement 20 miles per hour speed limits on roads across much of the southern half of the city. It has already enforced reductions from the 30mph limit on roads near schools; but now there’s growing support for a wider rollout.

Emergency vehicles like ambulances will be exempt – but the hope this that wider 20mph limits will persuade drivers of other vehicles to better share the road with each other, pedestrians, and cyclists. The rationale behind this in Birmingham applies to any other city in the country: the authorities want to reduce the severity and number of accidents. They aim to lower air and noise pollution, too.

Previous consultations showed stronger support from those who walk, cycle, and use public transport – so convincing those who primarily drive will be the key challenge. There is also widespread support amongst other key stakeholders: businesses, schools, the police, environmental groups, and transport and delivery groups.

Evidence from several towns and cities across England shows that the implementation of 20mph limits reduces the number and severity of road traffic collisions. A pedestrian, if struck by a vehicle driving at 20mph, is likely to suffer slight injuries. At 30mph they will probably be severely hurt; at 40mph or above, they are likely to be killed.

There are, of course, still concerns about the potential negative impacts of a 20mph speed limit – the most frequent being that it would increase congestion.


But that might not actually be true. While travelling at 20mph would obviously take longer than travelling at 30mph on a clear stretch of road, research shows that vehicles flow more smoothly through junctions at slower speeds. This would have a much greater impact in an urban environment, particularly in cities with older road networks.

Some may doubt that 20mph limits can reduce noise and air pollution. A study conducted in Graz, Austria, found that an introduction of 18mph limits back in 1992 led to a noise reduction up to 2.5 dB. Compared to 30mph, 20mph would mean three decibels less traffic noise. There is no conclusive study yet regarding the impact on the environment, but, as a result of reduced acceleration and braking, a 20mph limit may help to reduce fuel consumption and associated emissions.

 Ultimately, the driving issue – forgive the pun – is what impact all this will have on journey times. Plans in Birmingham, much like those elsewhere, still retain some roads at the 30mph or 40mph limit. This should mean most journeys wouldn’t be significantly affected; and, in the case of those urban roads littered with junctions, the improved traffic flow could actually reduce overall journey times.

Still, reducing speed limits will inevitably prompt some motorists to feel penalised. Many will assume it will be a hindrance, even if the evidence says journeys will take the same time at most, be much safer and pleasant for themselves and others, and consume less fuel. The only way to convince critics is by testing 20mph out first and then judging the results.

Luckily, we already have a few case studies to go on.

In the Sherwood area of Nottingham, which has had a full year of 20mph on residential roads, average speeds have gone down by 5.2 per cent. At the same time, casualties in road traffic collisions have decreased from an average of 9.4 per year before implementation, to 8.0 in the year following implementation; most of these were deemed “slight”, rather than severe. In Portsmouth, 20mph limits lowered casualties in road traffic collisions by a further 8 per cent than may have otherwise occurred. In Warrington, collisions in the 20mph speed limit areas fell by a whole 25 per cent; Bristol, Edinburgh, and Dublin have all seen similar results.

Across Europe and the United States, a number of cities have proposed or adopted 20mph or 30 km per hour (about 19mph) limits. New York City has led the way, implementing numerous neighbourhood-scale 20mph zones. Ten other US states also allow for 15 or 20mph limits, mostly in school zones and business districts. They are ubiquitous in the Netherlands, cover 80 per cent of Munich, and a network of 67 European NGOs have pressed the European Union to make 30kmph the normal limit, with 50kmph the exception.

Birmingham is the former centre of Britain’s motor manufacturing industry, something which explains why so much of the city is so geared (sorry) towards cars. As CityMetric editor Jonn Elledge has written in these pages before:

“Outside [the city centre] you quickly run into a world of six-lane highways and traffic jams that snarl up every rush hour because, in large chunks of the city, the only way to get to work is by road.”

So in some ways it seems strange that moves to improve travelling by road have taken so much longer to be proposed here than in other cities where public transport makes them less dependent on roads for daily commutes.

Safer roads, cleaner air, savings on fuel, and less traffic noise would all be welcome changes – and not just in Birmingham. It is one of 16 UK cities the European Commission has issued warnings to our government over due to lethal levels of pollution.

But for the new speed limits are really to affect change, they’ll be dependent on two things. One is motorists obeying the new law; the other is the authorities enforcing it. Time will tell.

 
 
 
 

Which nations control the materials required for renewables? Meet the new energy superpowers

Solar and wind power facilities in Bitterfeld, Germany. Image: Getty.

Imagine a world where every country has not only complied with the Paris climate agreement but has moved away from fossil fuels entirely. How would such a change affect global politics?

The 20th century was dominated by coal, oil and natural gas, but a shift to zero-emission energy generation and transport means a new set of elements will become key. Solar energy, for instance, still primarily uses silicon technology, for which the major raw material is the rock quartzite. Lithium represents the key limiting resource for most batteries – while rare earth metals, in particular “lanthanides” such as neodymium, are required for the magnets in wind turbine generators. Copper is the conductor of choice for wind power, being used in the generator windings, power cables, transformers and inverters.

In considering this future it is necessary to understand who wins and loses by a switch from carbon to silicon, copper, lithium, and rare earth metals.

The countries which dominate the production of fossil fuels will mostly be familiar:

The list of countries that would become the new “renewables superpowers” contains some familiar names, but also a few wild cards. The largest reserves of quartzite (for silicon production) are found in China, the US, and Russia – but also Brazil and Norway. The US and China are also major sources of copper, although their reserves are decreasing, which has pushed Chile, Peru, Congo and Indonesia to the fore.

Chile also has, by far, the largest reserves of lithium, ahead of China, Argentina and Australia. Factoring in lower-grade “resources” – which can’t yet be extracted – bumps Bolivia and the US onto the list. Finally, rare earth resources are greatest in China, Russia, Brazil – and Vietnam.

Of all the fossil fuel producing countries, it is the US, China, Russia and Canada that could most easily transition to green energy resources. In fact it is ironic that the US, perhaps the country most politically resistant to change, might be the least affected as far as raw materials are concerned. But it is important to note that a completely new set of countries will also find their natural resources are in high demand.

An OPEC for renewables?

The Organization of the Petroleum Exporting Countries (OPEC) is a group of 14 nations that together contain almost half the world’s oil production and most of its reserves. It is possible that a related group could be created for the major producers of renewable energy raw materials, shifting power away from the Middle East and towards central Africa and, especially, South America.

This is unlikely to happen peacefully. Control of oilfields was a driver behind many 20th-century conflicts and, going back further, European colonisation was driven by a desire for new sources of food, raw materials, minerals and – later – oil. The switch to renewable energy may cause something similar. As a new group of elements become valuable for turbines, solar panels or batteries, rich countries may ensure they have secure supplies through a new era of colonisation.

China has already started what may be termed “economic colonisation”, setting up major trade agreements to ensure raw material supply. In the past decade it has made a massive investment in African mining, while more recent agreements with countries such as Peru and Chile have spread Beijing’s economic influence in South America.

Or a new era of colonisation?

Given this background, two versions of the future can be envisaged. The first possibility is the evolution of a new OPEC-style organisation with the power to control vital resources including silicon, copper, lithium, and lanthanides. The second possibility involves 21st-century colonisation of developing countries, creating super-economies. In both futures there is the possibility that rival nations could cut off access to vital renewable energy resources, just as major oil and gas producers have done in the past.


On the positive side there is a significant difference between fossil fuels and the chemical elements needed for green energy. Oil and gas are consumable commodities. Once a natural gas power station is built, it must have a continuous supply of gas or it stops generating. Similarly, petrol-powered cars require a continued supply of crude oil to keep running.

In contrast, once a wind farm is built, electricity generation is only dependent on the wind (which won’t stop blowing any time soon) and there is no continuous need for neodymium for the magnets or copper for the generator windings. In other words solar, wind, and wave power require a one-off purchase in order to ensure long-term secure energy generation.

The shorter lifetime of cars and electronic devices means that there is an ongoing demand for lithium. Improved recycling processes would potentially overcome this continued need. Thus, once the infrastructure is in place access to coal, oil or gas can be denied, but you can’t shut off the sun or wind. It is on this basis that the US Department of Defense sees green energy as key to national security.

The ConversationA country that creates green energy infrastructure, before political and economic control shifts to a new group of “world powers”, will ensure it is less susceptible to future influence or to being held hostage by a lithium or copper giant. But late adopters will find their strategy comes at a high price. Finally, it will be important for countries with resources not to sell themselves cheaply to the first bidder in the hope of making quick money – because, as the major oil producers will find out over the next decades, nothing lasts forever.

Andrew Barron, Sêr Cymru Chair of Low Carbon Energy and Environment, Swansea University.

This article was originally published on The Conversation. Read the original article.