JMP EDA Transport Study South Marston Samantha Howell

JMP EDA Transport Study South Marston Samantha Howell Principal Transport Planner Strategic Growth and Regeneration Team

JMP EDA Transport Study • JMP commissioned in partnership by SBC and Highways Agency to assess the transport implications of the Eastern Development Area (EDA) • Initial assessment - 12, 000 dwellings • Further assessment of c 7, 000 dwellings to reflect lower quantum of development in Revised Proposed Submission Draft Core Strategy

Context • WSP Swindon Transport Strategy • South Marston Village Strategy • LDA Framework and Draft EDA SPD • NEW Masterplanning ‘Planning for Real’ Workshops

Scope of Study • Transport modeling at strategic and local level • SATURN – understands how traffic assigns across the wider network • PARAMICS – microsimulation model looking at EDA area including South Marston • Local model developed for all signalised junctions in the EDA area • Scenario testing: ‘worst case’, mid-range & ‘stretch’ • Appraisal of potential transport interventions/mitigation

South Marston • Stage 1: assessment of existing issues • Stage 2: future proofing potential solutions against impact of growth at the EDA

Stage 1 • Vehicle counts and site observations • Meetings with South Marston Parish Council, Traffic Sub-Group and NEW Masterplanning • Key issues: • Pedestrian and vehicular conflict at Pound Corner • Perception of rat-running, high volumes of through traffic and speeding • HGV’s getting lost or taking short cuts • Noise disturbance of speed humps

Stage 2 • Key questions: • Can the masterplanning principles set out by SBC/NEW Masterplanning be achieved in transport terms? • Are the ‘southern’ and ‘eastern’ link roads necessary? • What are the transport implications of Rowborough?

Scenario Testing* • 955 total dwellings (SBC) • 613 total dwellings (NEW Masterplanning Option 1 b) *includes potential brownfield development at Crown Timber and Thornhill Industrial Estate and assumes 35 dwellings per hectare

Options Tested • ‘Baseline’ – extended village, no mitigation, and connection to Rowborough • Southern Link Road (Thornhill Road/Old Vicarage Lane/Rowborough) • Eastern Link Road (Highworth Road to Rowborough • Combinations of the above

Baseline Assessment - Key findings • Increase in traffic but from relatively low base • Traffic not only related to expansion of village but increase in through traffic to EV destinations • Rowborough traffic impacts mainly on Keypoint / Old Vicarage Lane/ A 420 junctions • Queuing at Keypoint roundabout, particularly in the morning peak (increase in journey time variability) • PM peak traffic conditions are better than AM peak

Pound Corner • Northern end of Old Vicarage Lane could be realigned • New junction to the west of Pound Corner (as per NEW Masterplanning proposals) could be provided • Junction to either be signalised or mini roundabout • Signalised junction – improved crossing facilities for residents • Mini roundabout – less urbanised and provides opportunity for new ‘gateway feature’ • Old Vicarage Lane (Pound Corner to school) becomes local access only. Probably in northbound direction. Permits provision of new footway BUT NOT RECOMMENDED

Southern Link Road Direct/no connection to Rowborough

Southern Link Road Indirect connection to Rowborough

Southern Link Road – Key Findings • Direct connection to Rowborough increases journey times and leads to more queuing at Gablecross • Most of the traffic leaving/arriving from Rowborough is to / from the south (limited impact on South Marston) • Indirect connection and no connection to Rowborough provides improvement in journey times at Gablecross • Increased journey times are a consequence of heavy traffic on the A 420.

Eastern Link Road – Key Findings (indicative link Supermarine Roundabout) • Not a strong case in traffic terms • Modelling indicates that this would not be heavily utilised (much of the traffic ‘rat running’ through village is from the north and to the EV District Centre and employment areas south of the A 420) • Morning peak conditions are worst overall across the network but most of the traffic leaving Rowborough is travelling south onto the A 420, not north.

Other Considerations • In all scenarios, existing chicanes will not be appropriate for village roads carrying higher traffic volumes • Impact on journey times influenced by traffic on A 420 • Balance needs to be sought between priority for strategic and local traffic • Improvements to the A 419, White Hart Junction, Gablecross and A 420 / Old Vicarage Lane junctions are important in mitigating full impact of EV

Recommendations • • 20 mph zone in village (30 mph from Keypoint and A 420) Footway improvements Public rights of way and bridleways should be retained Psychological traffic calming, removal of chicanes and selective carriageway widening • Signalised crossroads at Gablecross junction • Further consideration new signalised junction east of the of A 420 / Old Vicarage Lane junction and links to. Rowborough

Next Steps • Finalising report • Any comments must be received by 5 pm on 22 nd March 2011 • South Marston Core Strategy Exhibition – here on 12 th April between 5 pm and 9 pm • Additional scenario testing and further consideration of options at Pound Corner and Old Vicarage Lane/A 420 Junction

Thank you. Any questions? Contact details E-mail: showell@swindon. gov. uk Tel: 01793 466500 www. swindon. gov. uk