Traffic impact of 3,930 houses at Hall Farm.
- paulstevens24
- Oct 23
- 11 min read
The main body of this blog was sent to me by a resident, who, having attended one of the University of Readings information meetings found themselves less than happy with the answers given to their questions about the likely impact of the additional traffic generated as an inevitable consequence of nearly 4,000 houses being built on green fields with very little in the way of existing transport infrastructure.
The transport data to support the Local Plan Update is available to view on the council’s website, link below to see all the evidence studies.
Link below to see the LPU Transport assessment report.
However, this is a bit of a struggle to read, never mind comprehend, particularly if you are a lay person. But the resident had a daughter, who worked for Google, who suggested Artificial Intelligence (AI) might help by creating an "Executive Summary" of the evidence.
I have taken the text generated by Gemini AI and given it a few tweaks to emphasise some key points and to make it more readable, but what I present below is not my opinion, it is an objective analysis of the traffic and transport issues building at Hall Farm presents.
Executive Summary: Strategic Impact Overview
The Loddon Garden Village (LGV) planning application, officially recognized as the Hall Farm / Loddon Valley Strategic Development Location (SDL), proposes the delivery of approximately 4,000 new homes. This scale of development is forecast to generate a severe and concentrated increase in traffic, estimated at a gross load of 2,000 Vehicles Per Hour (VPH) on the surrounding highway network during peak commuting periods.
The analysis confirms that the accommodation of this significant vehicular load is entirely contingent upon the coordinated and timely delivery of an extensive, complex, and high-cost Off-site Highway Mitigation Package (modelled as Scenario 1B in the Transport Assessment). This package includes vital strategic elements such as the new link over the M4 motorway and crucial upgrades to M4 Junction 11.
The key finding regarding mitigation sufficiency is that any failure in the timing, funding, or operational performance verification of these major hard infrastructure elements will result in catastrophic network degradation across Wokingham Borough and into neighbouring authorities.
A critical risk is identified in the fundamental conflict between the design of the hard infrastructure and the required soft mitigation goals. Specifically, the construction of the new M4 link road, open to all traffic, directly competes with the viability of the proposed sustainable transport strategy (Rapid Transit System, RTS), potentially undermining the mandated 7% modal shift target. This design inconsistency poses the highest risk to the long-term validity of the Transport Assessment.
Section 1: Contextualizing the Loddon Garden Village (LGV) Development
1.1 Project Scope and Policy Framework (LPU/SDL Designation)
The project is spearheaded by the University of Reading and partners, aiming to deliver up to 3,930 homes alongside essential supporting infrastructure. The LPU envisions the site as a self-sustaining "garden village" featuring substantial internal amenities, including two new primary schools, a new secondary school, a business hub, retail facilities, and healthcare services. If the application is approved and the LPU is deemed sound by Government Inspectors, the development of key infrastructure and the first phase of homes is anticipated to begin delivery from 2028.
1.2 Defining the Gross Vehicular Load: Analysis of the 4,000-Home Cohort
The instantaneous vehicular demand placed on the existing infrastructure at the height of the morning or evening commuting period is projected to be approximately 2,000 VPH. This large volume necessitates robust intervention across multiple road corridors simultaneously.
The premise of the "garden village" planning model relies heavily on achieving a high degree of trip internalisation, thereby reducing the net number of VPH exported onto the external network. Internalisation is critical for facilities like schools.
The Transport Assessment relies on analysis of pupil postcodes in the Wokingham borough to establish assumptions for on-site school usage: 57% of primary school pupils are projected to live within 1km of their school, rising to 72% for secondary school pupils.
If the amenities or educational provisions within the LGV are not delivered in a timely manner, or if residents exercise parental choice to utilize popular, established schools located outside the designated 1km catchment area, the high internalisation rates used in the model may not be realized.
This variance in behavioural choice would immediately convert intended internal trips into external VPH movements, meaning the net 2,000 VPH impact figure may be underestimated if social or market dynamics undermine the underlying internalisation assumptions. Such a failure would impose immediate, unintended network stress not accounted for within the mitigated modelling scenario (Scenario 1B).
1.3 Baseline Network Saturation (Pre-Development Conditions)
The region surrounding the proposed LGV site, particularly the B3270 corridor and routes connecting into Reading via Lower Earley, is characterized by existing significant congestion and delays. Historical context confirms the severe capacity constraints; prior large-scale projects, such as the Winnersh Relief Road (WRR), were explicitly implemented to "alleviate existing congestion" and manage traffic from earlier housing developments in the borough.
The necessity for the WRR demonstrates that the baseline highway network capacity is already fully saturated and operating near or above critical flow thresholds. Therefore, the addition of a further 2,000 VPH is physically and operationally unfeasible without a complete structural overhaul of the surrounding highway infrastructure.
Section 2: Hard Infrastructure Mitigation Package Efficacy
Interdependency and Delivery Risk of Mitigation
The mitigation package does not function as a series of isolated components; it is an interconnected, single system (Scenario 1B). The entire viability of the Transport Assessment hinges on the assumption that all elements are delivered in coordination and achieve their modelled capacity improvements.
If primary strategic links, such as the M4 J11 upgrades or the new M4 crossing structure, are delayed, face unforeseen construction constraints, or suffer funding shortfalls (potentially related to the necessary Section 278/38 works), the entire traffic load will be rerouted onto secondary local junctions, such as the Black Boy roundabout.
Such failure would negate the "no significant net detriment" conclusion reached for the strategic network. Consequently, planning approval must be conditioned not solely on financial commitments, but on the verifiable physical delivery and demonstrated operational performance of the primary strategic links prior to reaching key occupancy trigger points.
The Lower Earley Way Paradox.
A significant analytical contradiction exists at the junction of hard and soft mitigation strategies, termed the Lower Earley Way Paradox. The critical new M4 link road is necessary to handle the high volume of peak-hour car movements. However, this link is designed to be "open to all traffic". Reading Borough Council (RBC), the neighbouring authority, explicitly objected that a road designed this way will inevitably "encourage car travel to Reading via Lower Earley using congested and unsuitable roads".
The infrastructure designed to provide relief and distribute overall VPH outflow simultaneously generates new, induced vehicle flow directly into a highly sensitive, already congested, cross-boundary network area (Lower Earley). This design choice prioritizes raw car movement capacity over achieving the necessary modal shift, establishing a material cross-boundary operational conflict that requires resolution, potentially through bus-only priority measures on the link itself, a measure proposed by RBC transport officers.
Table 1: Key Off-Site Highway Mitigation Measures and Dependencies
Affected Corridor/Junction | Mitigation Measure | Strategic Purpose | Primary Risk Factor |
M4 J11 Interchange | Signal Optimisation & Lane Additions | Maintain Strategic Road Network (SRN) capacity | National Highways compliance and timing of delivery |
Lower Earley Way (B3270) | New M4 crossing link open to all traffic | Primary access and Reading/M4 distribution | Undermining sustainable transport goals through induced car trips |
Winnersh Relief Road (Mill Lane) | New access connection | Disperse flows north-eastward towards Wokingham | Coordination with existing WRR infrastructure and capacity |
B3270 Lower Earley Way | Signal Improvements and Monitoring | Enhance local urban capacity and flow management | Success is dependent on regional traffic volumes being mitigated upstream |
Section 3: Sustainable Transport Strategy and Modal Shift Reliance
3.3 Analysis of the Rapid Transit System (RTS) and Bus Priority
A key component designed to encourage mode shift is the proposed Rapid Transit System (RTS). The RTS is planned to commence operations as a bus service, with the long-term potential to adapt to new technologies such as autonomous shuttles. Proposed routes are intended to provide high-frequency connectivity to Central Reading, Wokingham Town Centre, Wokingham Station, and the Winnersh Triangle Park & Ride facility.
The Operational Risk of Delayed Modal Shift Infrastructure
Reading Borough Council (RBC) has expressed serious concerns regarding the viability of the bus service strategy, specifically citing the risk of a "long build out period and a short funding package for initial bus services". If the housing units are occupied over a long-phased development period (e.g., a decade) and the promised frequent and reliable bus network (RTS) relies on insufficient or time-limited initial funding, the earliest residents will immediately establish long-term car-dependent behaviours.
The process of retrospectively changing established car ownership and commuting habits is exceptionally difficult, risking the permanent failure to achieve the required 7% modal reduction across the entire cohort. For the RTS to successfully encourage modal shift, the services must be financially sustainable, sufficiently frequent, and achieve competitive journey times. This dictates that mandatory planning conditions must enforce the delivery of full bus priority infrastructure (e.g., dedicated priority lanes on key exits like the A327, as recommended by RBC) and guarantee necessary long-term subsidy for the RTS before predetermined low-level occupancy trigger points are reached.
Fragility of the Conservative Assumption
While the Transport Assessment adopted a conservative 7% reduction based on the demonstrated efficacy of targeted Smarter Choices programs, the success of these programs fundamentally relies on the sustainable alternatives being genuinely competitive with private vehicle use. The contradiction inherent in the M4 link design—creating efficient access for private cars—directly undermines the competitiveness of the RTS.
RBC highlighted that the new car-friendly bridge to Lower Earley Way will "certainly also encourage car travel," which will exacerbate congestion and delays for existing bus routes, making them "less attractive and less reliable". When the hard infrastructure (car routes) is highly efficient and the soft infrastructure (bus services) is rendered inefficient by the induced car traffic, the 7% assumption moves from a conservative estimate to a highly optimistic forecast.
Robust technical review necessitates a sensitivity analysis modelling the consequences of a zero or negative net modal shift, confirming the network outcomes if the site-specific 1.5% SDL uplift fails to materialize due to operational shortcomings.
Table 2: Risks to 7% Modal Shift Delivery
Challenge/Risk Area | Evidence from Consultation | Consequence on Transport Goals | Citations |
Priority Conflict | New M4 bridge open to all traffic, not restricted to public transport priority | Actively encourages private car commuting, directly undermining RTS use | |
Bus Reliability | Existing Lower Earley routes already face delays; new traffic worsens this | Jeopardizes RTS journey time and frequency goals, reducing competitiveness | |
Infrastructure Funding | Risk of short-term funding package for bus services during long build-out | Leads to entrenchment of car dependency among early residents | |
Internalisation Failure | High reliance on residents using on-site schools and amenities (57%-72%) | External trips increase if parental/consumer choice leads to external destinations |
Section 4: Cross-Boundary and Residual Network Impacts
4.1 Impact on Reading Borough Council (RBC) Network
The traffic generated by LGV necessitates movements into neighbouring authority areas, most notably Reading Borough Council (RBC). RBC’s primary material objection focuses on the severe consequence of induced traffic flow towards Central Reading, specifically via the already congested Lower Earley Way. The forecast increase in car journeys in this critical corridor will significantly intensify delays on bus routes operating within Lower Earley, making them "less attractive and less reliable".
This directly impairs RBC's ability to maintain mandated public transport service levels for its existing residents, representing an unacceptable externalization of congestion costs. RBC mandated that the LGV development must address the new car journeys generated by providing significantly enhanced public transport access to major destinations and must mandate the establishment of bus priority lanes on key exit roads (such as the A327) to actively counteract the induced private car travel.
Lack of Regional Transport Governance Alignment
The conflict between the Wokingham Borough Council/Developer proposal (a multi-use M4 link) and RBC’s primary transport objective (maintaining sustainable travel viability on the B3270) reveals a critical failure to establish consensus on cross-boundary infrastructure design. This structural conflict means that the most effective single hard mitigation measure (the M4 link) is also the most potent source of cross-boundary tension and residual regional impact.
The planning authority (WBC) must demonstrate how conditions imposed on the LGV developer will be legally and financially binding to mitigate adverse impacts on RBC's network, particularly concerning B3270 signalization and bus priority measures.
4.2 Cumulative Impacts and Strategic Development Context
The Loddon Garden Village is not an isolated development. Its impacts are cumulative and must be assessed in conjunction with traffic generated by other major committed and proposed sites within the Wokingham Local Plan Update, including the ongoing South Wokingham Extension and the Arborfield Garrison Strategic Development Location sites.
The Transport Assessment uses the Scenario 1B modelling to test the combined impact of all committed and proposed sites against the Reference Case, emphasizing the necessity of coordinating all mitigation efforts to ensure the entire network can absorb the total resulting traffic load.
Section 5: Conclusions and Strategic Recommendations
5.1 Summary of Mitigation Sufficiency and Key Success Factors
The proposed mitigation strategy for the Loddon Garden Village development, designed to manage the substantial 2,000 VPH peak traffic load, is technically comprehensive but inherently fragile. The accommodation of this development is not simply about building roads; it is about achieving complex behavioural change. Sufficiency hinges critically upon three factors:
1. The unconditional, coordinated, and timely delivery of the strategic highway links (M4 J11 improvements, M4 link road, and the Winnersh connection).
2. The verifiable, operational achievement of the 7% modal shift target, demanding reliable and competitive public transport services.
3. The effective resolution of cross-boundary impacts through infrastructure design that does not induce further congestion on neighbouring authority networks (Lower Earley Way).
5.2 Recommendations for Enhancing Robustness of Sustainable Transport Deliverables
To solidify the viability of the proposal and safeguard the integrity of the highway network, the following strategic conditions should be mandated:
1. Mandatory Bus Priority Infrastructure: The design of the new M4 Link to Lower Earley Way must be modified to incorporate dedicated, permanent Bus Priority Lanes or signalization that grants absolute priority to Rapid Transit System movements onto the B3270 corridor. This is essential to counteract the significant risk of induced car travel identified by Reading Borough Council.
2. Long-Term RTS Funding Guarantees: Section 106 agreements must enforce financial guarantees that ensure sustainable, high-frequency bus service funding for a minimum period of five years post-full occupation. This duration is necessary to ensure the services are reliably competitive with private vehicles during the critical phase of resident settling and habit formation.
3. Prioritised Soft Infrastructure Delivery: The full suite of soft infrastructure—including the 'My Journey' program, Personalized Travel Plan (PTP) distribution, and Mobility Hubs (identified in the Infrastructure Delivery Plan )—must be fully funded, functional, and actively promoted well in advance of the first residential occupations to immediately encourage non-car modes and prevent early reliance on private vehicles.
5.3 Recommendations Regarding Monitoring Mechanisms and Trigger Points
1. Establishment of Clear Degree of Saturation (DOS) Triggers: Planning consent must include clearly defined, measurable performance thresholds (such as DOS levels or delay metrics) for key junctions, including M4 J11, B3270 intersections, and monitored points within the Lower Earley network. The exceeding of these operational thresholds must trigger mandatory, pre-agreed financial contributions from the developer for immediate, adaptive mitigation measures.
2. Tripartite Monitoring and Governance Agreement: A formal agreement, such as a Memorandum of Understanding or a Section 278 agreement, must be established and legally enforced between Wokingham Borough Council, Reading Borough Council, and National Highways. This agreement is required to jointly oversee and monitor the performance of key cross-boundary corridors (specifically Lower Earley Way and M4 J11) and guarantee the timely management and funding of responsive, adaptive mitigation measures if the forecast network performance is not achieved.
Some serious issues identified here that the Inspectors will need to dig into. I hope to see as many of you as possible at 09.00, outside Shute End on November 18th, when the Inspectors arrive for the Examination in Public. Possibly also inside over the following four days of the examination itself? It promises to be an interesting few days ;-)
Paul Stevens (with help from Gemini AI) for SOLVE Hall Farm.
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