Union Street roundabout Turbo-style roundabouts the future? Patrick Lingwood Walking and Cycling Officer Bedford Borough Council

Union Street roundabout Turbo-style roundabouts the future? Patrick Lingwood Walking and Cycling Officer Bedford Borough Council

Presentation outline Local importance and problems we faced The evolution of the design Dutch Turbo-roundabout What it is and how it works Crisis and redesign Objections Redesign principles Picture gallery Did it work? Traffic capacity and queuing Traffic Speed Use of Zebras The importance of the design

Union Street roundabout A6 traffic Southbound A6 traffic Northbound Cycling and local traffic to/from station Union St Roundabout Railway Station Town Centre Bus Station

Union St Roundabout Railway station

2010 Post code plots of children cycling to Biddenham Upper School Union St Roundabout Biddenham Upper School

Pedestrian and Traffic Flows Busy multifunctional roundabout - flows per day (7am -7pm) 25,000 motorised vehicles 1000 lorries 500 buses 150 PTWs 550 cyclists 350 on-road and 200 off-road 3000 pedestrians 400 children

Clapham Rd Roff Avenue Union St roundabout Names of roads Union Street Tavistock Street

Railway station Union St Roundabout

DfT cyclist safety grant 2002 and 2012 36 casualties (8 serious) 12 Cyclists: 8 (1 serious) involved cyclists circulating 1 serious a cyclist crossing at the arms 24 others 8 Pedestrians (3 serious) crossing at arms 5 PTWs: (1 serious) 13 Car drivers/passengers (2 serious) The 10 year cost of accidents 1,823,000

Bicycle flows and accidents 350 on road & 200 off road Scale 1pt = 10 On-road Off-road

Evolution of design DfT Cyclist Safety Bid

3 Objectives Safety: Reduce all injury accidents especially to cyclists and pedestrians Sustainability: Encourage walking and cycling Traffic: no significant impact on capacity or queuing

Designs evaluated Options compared Injuries Savings Savings Traffic impact 10 years costs KSI Slight KSI Slight KSI Slight 0 1 Do Nothing 8 24 0 0-1481 -342-1,823 Base 2 Compact on road 3 Compact offroad 4 Circulatory annular 1 14 7 10 1,296 200 1,438 Yes 3 15 5 9 926 214 1,140 Yes 5 22 3 2 556 28 584 No 5 Spiral annular 2 14 6 10 1,111 200 1,059 Yes 6 Signalised 2 14 6 10 1,111 200 1,311 Yes 7 Turboroundabout 2 14 6 10 1,111 200 1,311 No

12m central island radius 0m 10m 30m 44m ICD Roff Avenue/Tavistock Street/Clapham Road/Union Street Roundabout

Option submitted to DfT Raised dividers

2 lane entries 2 circulating lanes where needed Compact style entry, circulating, exit deflection Raised dividers Spiral lanes Zebras and cycle crossings

Dutch findings: Capacity and safety Capacity Higher capacity than single lane compact roundabout Safety 40-70% safer than alternative junctions and safer than equivalent 2 lane (Dutch) concentric roundabouts spiral lanes with fewer conflict points slower speeds enforced by geometry

Crisis and Redesign

Raised Dividers Controversy Objections by MAG (Motorcycle Action Group) Meetings with DfT and Sustrans Redesign Same principles speed reduction and spiral roundabout raised dividers replaced by virtual dividers opportunity to improve the design

Raised dividers removed Extended kerbs with vertical posts Build outs on central island

How the virtual dividers work Following lane results in 3 similar radii of curve Straightlining results in tighter radius of curve at extended kerbs

Picture Gallery

Did it work?

Data collection Data was collected at the roundabout at 3 times (7am 7pm weekdays): 2007: (Compact) when the roundabout was operating as a single lane compact roundabout because of extended road works on gas mains 2012: (Before) when the roundabout was operating with typical unmarked wide 2 lane circulating carriageway 2014 (After) when the roundabout had been changed to a turbo-style roundabout with separated lanes and Zebra crossings on all arms

All day traffic capacity 2007 2012 2014 Car Lgv Ogv1 Ogv2 Bus Mc Pc 0 5000 10000 15000 20000 25000 30000

Peak time capacity 2007 PM 2012 PM 2014 PM 2007 AM 2012 AM Car Lgv Ogv1 Ogv2 Bus Mc Pc 2014 AM 0 500 1000 1500 2000 2500 3000

160 140 120 100 AM Peak time Queuing (Roff Avenue metres) 2007 2012 2014 80 60 40 20 0 07:00 07:10 07:20 07:30 07:40 07:50 08:00 08:10 08:20 08:30 08:40 08:50

Speed surveys (circulatory carriageway free flow mph) 25 20 15 Before After 4mph A 8mph B 10 5 6mph 0-5 mph 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Typical cycle speed

Benefits of slower speeds More comfortable on-road cycling Small difference between cyclist and vehicle speed Safer (cycling) Zebra crossing drivers more aware and willing to stop Easier to get on roundabout lower gap acceptance

Crossing at the Zebras 2500 2000 1500 Zebra/Pelican Without help 1000 500 0 2012 Adults 2012 Children 2012 Cyclists 2014 Adults 2014 Children 2014 Cyclists

Conclusion So far, it all looks hopeful Safety and capacity advantages of Dutch turbo-roundabouts Virtual dividers make it easier to retrofit Potential design for other busy urban roundabouts?

Union St Roundabout Turbostyle Source Brilon 2008

A scene of smooth tranquillity it is so much easier to cross the roads with the pedestrian crossings and the sense of intimidation has gone for car and van drivers, too Graeme Hay BMF Patrick Lingwood Patrick.lingwood@bedford.gov.uk