Junction 15 members Briefing

1. Junction 15 members Briefing Jason Humm - Head of Highways and Transport Rob Rossiter - Strategic Allocations Transport Manager

2. Aims and objectives • Strategic Context • Scheme background • Scheme progress since previous meeting • Delivery mechanism • Outline scheme detail • Local Concerns/Suggestions • Communication of Further Progress • Questions

3. Strategic context

4. Scheme background • Increase the capacity of the junction, reduce congestion and improve safety • Accommodate substantial planned growth in Swindon including Commonhead, Kingsdown and NEV developments • Jointly funded by Highways England’s Growth and Housing Fund and match funding provided by developer contributions secured by SBC • Estimated up to £10m scheme cost • 12 – 18 months construction, complete late 2019/early 2020

5. Progress/Changes since Dec 2016 • CommonheadS106 variation proposals approved by Planning Committee in April 2017, confirming developer contribution approach to Junction 15 delivery • Detailed Design of Junction 15 commissioned by Commonhead Developers in March 2017 • Draft Funding Agreement received from HE with SBC amendments • Agreement that HE to lead on scheme delivery

6. Delivery Mechanism • WSP Carrying out detailed design on behalf of Commonhead developers – Persimmon and Redrow • Scheme designed to Highways England approval specification • HE’s framework / tender process to deliver scheme through contractor • Contractor managed by HE • Cross authority agreements to be engrossed to facilitate work on SBC network

7. Scheme detail • Increased capacity southbound off-slip to Commonhead Roundabout • Widening the southbound carriageway of the A419 between the Commonhead Interchange and Junction 15 to 3 lanes • Dedicated left-turn slip road for traffic travelling from the A419 to the M4 eastbound towards London • Widen slip roads off the M4 onto the Junction 15 roundabout • Widen A346 approach to the junction from Marlborough • Improved signal operation

11. Local concerns/suggestions • Extension of M4 (west) filter lane up Plough Hill • Scheme extends flare length and increases lanes at roundabout entry, without facilitating high traffic speeds creating safety concerns. Filter lane not feasible without new westbound slip and additional lane on the M4. • Reduced length ‘climbing lane’ on Marlborough Rd south to accommodate additional access lane to Junction 15 • Climbing lanes required as per HE specification, to avoid significant congestion caused by slow moving HGV’s. • New Traffic light sequencing at the foot of the A436 (Plough Hill) • Scheme addresses this • Amendments to New Road Junction – left in/out slips • Would require dualling of A436 and significant land purchase • Rat running during construction • HE propose for this to be addressed/agreed through the Traffic Management Plan for the Junction works

12. Communication of Further Progress • Upon completion of detailed design, presentation to stakeholders to be arranged • HE to communicate scheme progress updates • SBC to notify HE and delivery contractor of local concerns during design and construction • Frequent scheduled meetings between SBC, HE and delivery contractor • Continuation of Junction 15 Information Events