Traffic Evaporation

“You get the traffic you build for” is an axiom that all of Oxfordshire’s localities should live by. Years of research conclude that building more roads generates additional traffic, and reducing the amount of road-space evaporates some traffic.

This post is about evaporation. As the image implies, some of the traffic switches to other modes; some chooses completely different routes. It’s fallacious to think of traffic as water, which has to find a way through. Some of it actually goes away.

In terms of the research, Rachel Aldred in Motor traffic on urban minor and major roads: impacts on pedestrian and cyclist injuries (page 2) cites Cairns S, Hass-Klau C and Goodwin P (1998) Traffic Impact of Highway Capacity Reductions: Assessment of the Evidence. Landor Publishing, London, UK).

Todd Litman in Generated Traffic and Induced Travel: Implications for Transport Planning (page 5) cites that same Cairns et al (1998) paper, plus five others:

Such [induced demand] impacts can also occur in reverse: reducing urban roadway capacity often reduces total vehicle travel (Cairns, Hass-Klau and Goodwin 1998; Cervero 2006; CNU 2011; ITDP 2012; Miller 2006) which is sometimes called traffic evaporation (EC 2004).

Profile in Courage: Waltham Forest Cllr Clyde Loakes

Waltham Forest Councillor Clyde Loakes (pictured) delivered this speech at the Healthy Streets conference in London, 2018. His speech was transcribed on Twitter by Chris Kenyon (@boxbikelondon). (Click here for the original Twitter thread.) Here is Chris’ rough transcription of Clyde’s speech:

I have been a councillor for a long time, since I was 27… I’ve spent more time dabbling in bins than anyone should and I have the scars from looking into car parking schemes.

I spent years talking about encouraging a shift to bikes and walking without actually doing the things that make a difference. If I am honest – I was tinkering with parking schemes and pandering to car owners. I was not delivering for our community.

Then I got a chance to do something extraordinary. We won our Better Waltham Forest mini-Holland bid with low traffic neighbourhoods and protected bike lanes. We had signed up to deliver a huge public health implementation at pace.

Surprisingly our plans for a human centric, better community provoked rage, protest and the use of four-letter anglo saxon words from a 500-strong group. Removing £100 million from our social services budget, nothing, but if you talk about parking…

But a ground-up movement of residents and fellow councillors championed a progressive intervention for our streets, making them better for everyone. We went house to house and made the case.

In the local elections in May this year and worried by what was being said on social media, the local press, in public meetings and on protests – I drafted my resignation letter.

But guess what… I got the largest majority I have ever had. Every Labour councillor that had backed the scheme showed a significant increase in votes. It was amazing. So it was popular once built… but was it impactful?

We commissioned Kings College to see the what the health impact of the scheme was. Again if you believed the local press – no one was now walking or cycling as a result of our work. Again… I prepared my resignation letter.

The impact of what we have done is enormous and it’s impacted public health measurably. DfT data shows that not only did the borough have the largest increase in walking last year, the increase is so large that life expectancy has been extended for residents.

Tavistock Place, Camden (London)

The “Inspector’s Report on the Torrington Place to Tavistock Place Public Inquiry” was released on May 18 and is available here. Read more

Pedal & Post

Did you know that Oxford is home to one of the biggest “last-mile” cargo-bike logistics operations in the UK? Pedal & Post has 10 cargo-bikes covering the entirety of the city every day.

 

More than 25% of disabled commutes in Cambridge are by bike

Riding a bike may be easier than walking for two-thirds of disabled cyclists, but they often remain invisible to society. Many don’t realise that more than a quarter of disabled commutes in this university city are made by bike.

Read more

Fair-weather cycling?

Do people cycle in all seasons? In Copenhagen, pictured above, 75% of the city residents keep cycling through the winter months.

This study of Swedish households found active-travel commuters “to be much less sensitive to weather changes than non-commuters”.

There is even such a thing as a Winter Cycling Congress.

Stevenage’s unloved bike lanes

The UK town of Stevenage (pop 88,000) famously built miles of segregated cycleways in the 1960s … only to see them disused.

Carlton Reid tells the story.

Squint at Stevenage’s extensive 1960s protected cycleway network and you could be in the Netherlands – except for the lack of people on bikes. So why did the New Town’s residents choose the motor car over the bicycle?

 

Dronning Street in Copenhagen

Car space on Dronning Louises Bridge in Copenhagen was reduced to increase space for cycling, pedestrians, and buses. The result was an increase in cycling by 60%, walking by 165%, bus use by 5%, and increase from 81,000 to 97,000 using the bridge.

Source.

Motorised traffic journey times after space-reduction

London’s Cycle Superhighways (CSHs) offer one example of a reallocation of road space between cycles and cars. The graphs above and below indicate the impact on journey times for motorised traffic, as of November 2017. These are from Transport for London.

Journey times are certainly up. But for the first time, they are actually falling. This reflects in part traffic evaporation as commuters switch to other modes.

And keep in mind the overall increase in *people* being moved along these routes:

Recent monitoring data shows that central London segregated cycle lanes are moving five times more people per square metre than the main carriageway

– Transport for London, FOI request response