Filtered Permeability: Giving the Advantage to the Bike Steve Melia

Manual for Streets (DfT, 2007) Street networks should, in general, be connected…or ‘permeable’

Manual for Streets (DfT, 2007) Why?

Manual for Streets (DfT, 2007) Connected or ‘permeable’ networks…lead to a more even spread of motor traffic throughout the area… …more traffic (and more CO 2 ) from any given road capacity

Manual for Streets (DfT, 2007) Connected or ‘permeable’ networks encourage walking and cycling…. Is this claim justified?

Freiburg – 26% of trips by car

Through routes 30 Km/h Homezones/ Calmed Pedestrianised Industrial Frieburg: Channelling Through Traffic

Freiburg Cycle Network

Vauban, Reiselfeld: Culs de Sac

Why do some people think that permeable networks for cars promote walking and cycling?

Sacramento, California ‘Traditional’ ‘Suburban’ From: Handy, Cao & Monkhtarian (2005)

Sacramento, California ‘Traditional’ ‘Suburban’ From: Handy, Cao & Monkhtarian (2005) 18% more car miles, on average “RAW” DIFFERENCE

‘Traditional’ ‘Suburban’ Different people, Different circumstances

‘Traditional’ ‘Suburban’ So does the grid layout actually make any difference?

‘Traditional’ ‘Suburban’ Some studies: no Others: yes – but small

Surrey – Regression Results: From: Hickman & Banister (UTSG, 2008) Socio-economic: 28% Land Use: 9%

Permeable Grids: Make it easier to walk/cycle… But also make it easier to drive

Filtered Permeability Maximises permeability for bikes, buses, pedestrians Restricts it for cars

Groningen – 60% of trips by bicycle

‘coarse grain’ network of roads for cars

Groningen – ‘coarse grain’ network of roads for cars Groningen – ‘fine grain’ network for cycling

Groningen Cycle Path (& pavement)

Groningen – Cycle Bridge From City Centre

Groningen – Bus gate with cycle bypass

Zwolle: Cycle Tunnel with separate pavement

NEW CROW GUIDELINES (2007)

Manual for Streets (DfT, 2007) Pedestrians and cyclists should generally be accommodated on streets rather than routes segregated from motor traffic...

Manual for Streets (DfT, 2007) Note the get-out clause… Pedestrians and cyclists should generally be accommodated on streets rather than routes segregated from motor traffic...

Cycle Infrastructure Design Consultation Draft (DfT, 2007) cycle and pedestrian networks need to be more permeable than is usually possible or desirable for motor traffic. To achieve this local cycle networks might include quiet residential roads, paths alongside rivers and canals, disused railways, and sometimes conversion of existing footways…

Ecotowns Transport Worksheet Filtered Permeability: “…separating the sustainable modes from private motor traffic in order to give them an advantage in terms of speed, distance and convenience”

Refer to Ecotowns Worksheet (& European guidance) Challenge the Conventional Wisdom on Permeability and Segregation And… For UK Cycle Planners:

Give the advantage to the Bike! Articles in: Town & Country Planning Local Transport Today Cycle Magazine On: