Tag Archives: 20mph

20mph saves emissions, energy AND lives

The 20mph debate rages on in Bristol, with murmurings of potential reversal, Bristol Cycle Campaign want to shed some facts on an important aspect – Energy and Emissions. We’ve even got a handy infographic.

One controversial argument often heard is that a vehicle travelling at 20mph has higher fuel consumption and emissions than at 30mph. Whilst it is true that the gearing on most passenger cars means that traveling on an empty motorway at 20 instead of 30 would use more fuel for the same distance, the same is not true in urban areas. Even during uncongested times these roads have junctions and traffic lights. It is almost impossible to safely navigate a city without stopping and starting.

Take a 4km journey with 7 stops 500m apart. A car accelerating to 30mph from one stop to the next at a steady rate of 5mph per second would take 6 seconds to reach 30mph, it would then cruise at 30mph for 31 seconds before braking for 7 seconds. The 6 second acceleration phase uses over twice the amount of energy as the 30 seconds at steady speed. The braking phase then wastes all the energy. If the car weighs 1384kg, the average weight of a passenger car in the EU, has a drag factor of 1 and is 25% efficient, the overall energy consumed is 2.2 kWh.

If the speed limit on this road was 20mph instead of 30 this car would consume 1.4 kWh.

A common argument against 20mph is that it is difficult to stick to. As most passenger cars are optimised for driving on empty country roads and can reach speeds far in excess of any national speed limit, it is not surprising sticking to 20 is tricky. However, if air pollution and climate change are considered important, the solution is to surely change the vehicles we are using to move around the city. Yet the trend is still for bigger and heavier cars. Take the journey above, the raw energy needed to shift an average 77kg UK resident, with no steel cage, is 0.11 kWh. Doing it on a 20kg bike uses 1.1 times this energy (0.12kWh), in a two seater electrically powered light Renault twizzy, this figure is double (0.2kWh), in an average weight and average aerodynamically efficient petrol powered vehicle it is 20 times this. In an SUV it is nearly 30 times (3.31kWh). Some newer cars now have adjustable speed limiters that can be set to a specific speed and make it harder (but not impossible) to exceed it.

Another emission source rarely considered is non-exhaust emissions. These originate from tyre, brake, engine and road wear and contribute more than exhaust emissions to particulate matter pollution in our cities. Basically, the greater the force exerted on the tyre, brake, road or engine, the greater the wear rate. Reducing vehicle weight and speed limits reduces wear and tear, reducing particles in the air and reducing the number of times you need to change your tyres, brakes, engine components and the amount of tarmac that goes to landfill (unlike rail tracks you can’t recycle tarmac). These particulates are one of the main reasons tens of thousands of tonnes of autumn leaves end up in landfill sites every year, instead of contributing to our gas grid and food supply.

Reducing our cities’ speed limits means shifting the huge vehicles we choose to drive is more efficient, fewer emissions are generated and drivers save money. Most importantly, less energy bouncing around the city makes it more likely people will be encouraged to opt for one of the lower energy options.

The Mayor’s leaky boat – a parable of RPS and 20mph

Settle down while we tell you a story:

Imagine, if you will, the King of Bristol.

He sets sail in a big boat, given to him by a chap wearing red trousers. OK, says the King, I know Red Trousers has given me a leaky boat, but I’m sure it’ll stay afloat for a while.

But to his horror, the King discovers a giant hole in the bottom of the boat as soon as he sets sail. Water is gushing in, and the other passengers are turning mutinous!

The King desperately looks round for things to jettison to stop the boat sinking further, or at least to distract attention.

There’s no dead cat to hand, but then he finds just what he needs! Two heavy-looking boxes put there by Red Trousers, one marked “20mph”, the other marked “RPS”.

Over the side they go.

Some of the passengers seem happy, at least for a while, even as the boat continues to sink…

There are rumours circulating that Mayor Rees is seriously considering scaling back two of Bristol’s most progressive transport policies of recent years: residents’ parking schemes and 20mph zones.

BCyC can only hope those rumours are not true. We feel sure our Mayor would not attempt to gain cheap publicity, and distraction from the Council’s financial crisis, by ditching these two policies which have provided huge benefits in increasing cycle and pedestrian safety and preventing Bristol’s suburbs becoming one huge commuter car park.

Can Bristol Council confirm that any Council-led initiative to scrap or scale back these initiatives is firmly not on the Mayor’s agenda?

Joint Spatial Plan and Transport Study Consultation – have your say

Update  West of England Joint Transport Study Consultation Nov 2016 – our response

Will Greater Bristol ever become a true Cycling City? The Joint Spatial Plan sets out how to build 85,000 new houses and the modern transport links for a growing region over the next 20 years. It’s out for consultation until 19th December but even Bristol Mayor Marvin Rees is calling for more ambition.

Overall we feel not much has changed since our initial response in January Joint Spatial Plan and Joint Transport Study – our response. We encourage everyone to respond to the sensible questions in the consultation and to read the Transport Vision Summary Document. Some points we picked up:

  • current mode share of cars is 55% but needs to fall to 43% just to keep congestion at current level.
  • The study makes use of an  iconic image that says it all really.
  • Distance is critical for walking & cycling. Quality is next. Unless the Spatial Plan reduces the need for longer commutes it will be impossible for large numbers to make healthy & sustainable transport choices.
  • Total investment of £7.5 billion Transport Vision for delivery over the next twenty years, £0.4 billion for walking/cycling.
  • Proposal for ‘more strategic  cycling and walking corridors with better infrastructure’ is welcome but only by taking a whole carriageway corridor approach will change be possible.
  • There is a promising statement that ‘diversion of through traffic movements frees up highway space for sustainable transport modes’
  • Overall it appears that there is a projected increase in active travel modes by only 6% over the whole period. We consider this to be hopelessly inadequate to the scale of the health challenge we face.

There is a consultation video and some Frequently Asked Questions which provide more information and an overview of the issues. These are the main questions in the consultation:

  • The level of ambition in the Transport Vision, is it about right, too ambitious or not ambitious enough?
  • Whether the balance between different transport modes is right? Is there too much emphasis on public transport and cycling, or not enough?
  • How best to manage traffic? How radical should we be in our treatment of `through’ traffic?
  • What our options are to raise funds to deliver the Transport Vision?
  • What infrastructure should be provided to support the emerging development locations: schools, libraries, utilities (including broadband) and transport?

There’s a lot of good information on current levels of cycling in the 2015 report Bike Life – Taking the pulse of bike life in Bristol.

At the same time you should also respond to the Bristol Council Corporate Strategy consultation 2017-2022 – good for cycling?.

This graph shows the travel modes that a sensible transport policy would enable people to choose. At present our view is that it’s the hostility of the cycling environment that means this mode above all others is vastly underused.

chart-of-transport-modes-suitability-by-distance

 

There is a transport and infrastructure workshop on Wednesday 7 December 10.30am-12.30pm at MShed, Princes Wharf, Wapping Rd, Bristol BS1 4RN. You will need to register your free place.

jointtransportvision2016spendmodes_list

There will be further discussion on the Bristol Cycling Campaign response to this consultation at the December meeting of our Infrastructure Forum on Thursday 8th Dec, see our  Diary page.

How to campaign for Space for Cycling? Bristol workshop 10th Dec

Cycling UK and the Bristol Cycling Campaign are excited to host a Space for Cycling workshop in Bristol.

The aim of the event is to engage with local campaign groups, council members and the wider public in the West of England, to share expertise and ideas, to network and to gear up for the next stage in the Space for Cycling campaign!

Date: 10 December 2016
Cost: Donation or free

Register your interest here

The day will consist of a series of workshops, below is the day’s agenda:

10:00-10:30 Registration/Networking
10:30-11:00 Opening plenary
11:00-13:00 Workshop 1: Creating a ‘Tube map‘ network of cycle-friendly routes – using the Propensity to Cycle Tool and Google Drawing 
Workshop 2: Forming/Running a Campaign + intro to online webtools
13:00-14:00 Lunch
14:00-14-55 Workshop 3: Cyclescape – what is it and how can you use it?
Workshop 4: National political context and lobbying your local authority – a chance to ask your Councillors what works!
14:55-15:00 Tea break/find rooms
15:00-15:55 Workshop 5: Infrastructure safari/auditing using the Cycle Environment Assessment Tool
Workshop 6: Local campaigning stories – experiences from Bristol
Workshop 7: Battling ‘bikelash’ – media strategy
15:55-16:00 Tea break/find rooms
16:00-16:30 End plenary

Venue: St James Priory

Time: Please arrive at 10:00 for a 10:30 start.  Event will end at 16:30.

Register your interest here

Bristol Council Corporate Strategy consultation 2017-2022 – good for cycling?

Bristol Council has published the Corporate Strategy consultation 2017-2022. There are immensely hard choices to be made. Traditionally this means that those at the bottom of the pile are hit hardest. In transport terms, this means those who choose the cheapest and healthiest options of walking and cycling.

What does the strategy have say about cycling?

[bs_notification type=”danger” dismissible=”false”]Headline Action: Use the consultation to ask that walking and cycling be considered as strategic priorities rather than afterthoughts.[/bs_notification]

Mayor Marvin Rees places equality and health at the centre of his plans, and aims to “improve our transport to connect people to opportunity and tackle congestion”. In his ‘open letter to Bristol‘ he says:

We need to develop an understanding of where we want the city to be in four years and beyond and ensure we have the council operating in a way that will get us there. […] We have to reinvent the role of Bristol City Council in light of the available finances. It must maintain its leadership role and must continue to fight for good outcomes for people from the city. But we will have to work in new ways. This includes taking a strategic approach to identify what can be done better and more cost effectively.

There is a strong statement on buses and public transport. Much of this could apply to cycling and walking – try swapping those terms in the following paragraph:

In seeking to tackle congestion, the council needs to work with others to promote public transport use by creating better priority for buses on the road network, by improving the attractiveness of bus travel, especially through integrated ticketing, and by delivering major public transport improvement programmes such as MetroBus and MetroWest rail. The particular geography of the city, with its hills, river crossings and rail lines, as well as its historic road layout, present unique challenges in seeking to improve cross-city connectivity. Money to invest in transport infrastructure is hard to come by and serious thought needs to be given to new ways of generating funding for the future, we have set up a Congestion Task Group and all options will be explored.

Instead, we get this limp and frankly outrageous statement based on the false premise that it is hills rather than road danger that deters people from cycling:

Encouraging more walking and cycling in a hilly city continues to be a challenge, as indeed does increasing participation in order to promote healthy lifestyles, but we need to build on previous years’ success in securing Government money to invest more in cycle tracks, safe routes and crossings.

It is clear that there is no intention to challenge the status quo or find new ways of working. Any change will continue to be expensively and ineffectually bolted on the side based on whatever small pots of funding can be secured.

Other points relating to cycling are:

  • To have delivered on our promise to review residents’ parking schemes and 20mph speed limits with local councillors and be able to respond to community priorities for highway improvements.
    Delivering a review? Is this progress?
  • To produce a comprehensive Bristol Transport Plan with a particular focus on the steps required to deliver against the key objective of tackling congestion.
    This could be very useful in setting strategic objectives, if the political will is there. See for example what London has achieved.
  • Develop an air quality action plan. Through the Mayoral Combined Authority, pursue powers to introduce low emission or clean air zones.
    Another promising objective that could be used to great effect.
  • Remove the funding for local traffic schemes currently devolved to Neighbourhood Partnerships (RS3) –
    Currently Neighbourhood Partnerships are given £350k to provide smaller local traffic schemes, which could be removed generating (including staff costs) a £410k saving. Note that delivery of current planned schemes may be impacted.
    A mixed blessing. Much of the focus of this pot was used for ‘tinkering’ schemes that fiddled at the margins of the main issues. Lots of crossings for example, without considering options for reducing traffic and rat-running. Nevertheless, local schemes can have significant effects.
  • Agree a West of England Joint Spatial Plan and Joint Transport Plan that prioritises investment in the urban area.
    Another promising objective that could be used to great effect. There will also be an Economic Plan for the city centre, and revisions to the Bristol Local Plan that could in theory offer and forward thinking and evidence lead approach to planning for a city ‘where cycling and walking are so easy that everyone does it’ (that’s from the BCyC vision statement in case you don’t recognise it).

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