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Why more roads = more traffic jams

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We need to publicize these studies far and wide, so that every American understands them. Without this knowledge, we 100% lack the basis for any kind of sensible growth policies in this country.

Grids, which are the most efficient way of moving traffic (because options!) are the counter-intuitive best practice.

Any other best practices?

I lease a small car, which forces me to budget my miles.  I average 9,000 mpy. 

DrivingPrivate vehicles are by far the largest source of travel emissions.  If you own a car and drive it regularly then vehicle emissions are likely be the dominant share of your travel footprint.  To reduce your driving footprint you either need to drive less, drive more efficiently, changing your vehicle or share more journeys.

Driving Less

As we have already discussed, reducing travel is the cheapest and most effective way to minimise your travel footprint, but it can be very difficult depending on your travel patterns.

Aside from reducing your total mileage, limiting the number of short trips you make is a good way to improve your footprint.  Short trips involve a lot of stopping, starting and parking, which makes them an inefficient use of fuel.  Walking or cycling for short journeys is a simple, and often quite pleasant, way to reduce emissions.

A more extreme way to ensure you drive less is to simply to get rid of your car.  Growing access to car share schemes in big cities is making this idea more viable for many people.  This idea is particularly appealing to city dwellers who like to drive occasionally but do their normal commuting on public transport, bike or foot.

Improving fuel economy

We can often increase the fuel economy we achieve in numerous ways without changing vehicles.

Cars use energy to accelerate, brake, power gadgets and overcome resistance from the air and road.  Reducing how much energy is used doing these things will improve the fuel economy of your car.  This can be done by avoiding rapid acceleration and braking, ensuring tyres are correctly inflated, limiting unnecessary weight in the car, removing roof boxes if not used regularly, and avoiding traffic when possible.

In terms of highway miles the most important factor is how fast you drive.  Combustion engine cars tend to be most efficient from 40-60 mph ( 64-96 km/h) in their highest gear.  Increasing this to 70 mph (113 km/h) can reduce fuel efficiency by as much as 30%.  So driving highway miles at a moderate speed in the highest gear tends to be the most efficient way to drive.

Changing Vehicles

As we showed earlier changing the vehicle you use can have a dramatic effect on your carbon footprint.  To illustrate these reductions we will compare the emissions of different vehicles assuming only the driver is on board.  We will also add a small diesel car, and vary the source of the electric cars electricity in order to compare emissions based on different generation technology.

Our new example looks like this:

image: image-557736a43b86e-DCHp.gif

With only the driver to transport, both the motorbike and scooter are less carbon intensive per kilometre than all but the renewably powered electric car.  For petrol cars carbon intensity falls as fuel economy rises, from 499 g CO2e/km for the 15 MPG car down to 190 g CO2e/km for the 45 MPG hybrid.

Once again it is useful to break these numbers down into direct emissions, indirect emissions and vehicle manufacturing.

image: image-557736a539b9b-Uy1C.gif

From this breakdown we can see direct emissions still dominate vehicles using oil based fuels, but that manufacturing emissions become more and more important for low-carbon vehicles.

We can make these numbers more tangible by choosing an example.  Let’s assume you drive 10,000 km a year by yourself.   In the large car this will result in 5 t CO2e, in the medium car 3 t CO2e, in the hybrid or small diesel 2 t CO2e, in the scooter 1 t CO2e and with the solar powered electric car around 700 kg CO2e.  The scope to reduce emissions by changing vehicle is clear.

If you are looking at reducing your travel footprint but still want the convenience of owning a vehicle, the main options are petrol, diesel, hybrid, electric or motorbike.  Once again we will not discuss biofuels as their availability and carbon intensity vary greatly depending on location and technology used.

Wow that was thorough. Are there electric cars where you are? Because they're all over California. 

I've seen only a few Teslae here.

No Priuses, Volts, or Leafs? That's unfortunate.

Yes, there are Priuses but I block them from my memory.

LOL, why?

I only think of them in passing.  ;-) 

Nothing inspires you about Prius, eh?

They get admirable gas mileage.  

I guess that's inspiring.

Yes, they are somewhat inspiring.

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