In the mid-1960s, the newly created Greater London Council (GLC) developed a plan for four concentric “Ringways” (ring roads) plus major radial routes. The goal was to handle rising car ownership and congestion by creating high-speed routes around and across London. This planning set the stage for the urban expressway projects that followed—and for the later shift toward a single outer orbital motorway.
Construction began on the “Western Avenue Extension” project in west London, later known as the Westway. It was intended to provide a fast link from the A40 into inner London and to connect with planned Ringway routes. Building it required demolition and major disruption in dense residential areas, foreshadowing the public backlash to urban motorway building.
A major new approach road for the Blackwall Tunnel on the south side opened as part of the wider expressway building program in east and southeast London. This corridor later formed part of the East Cross Route, designed as a key section of Ringway 1 (the “Motorway Box”). It illustrates how some Ringways-linked construction proceeded even before the broader plan was settled.
A public inquiry into the Greater London Development Plan (GLDP) began, giving formal scrutiny to the GLC’s motorway proposals. The inquiry became a focal point for tens of thousands of objections, with road building emerging as the most contested part of the plan. This process helped shift the political and planning environment away from large-scale urban motorways.
The Westway (opened as A40(M)) and the West Cross Route opened to traffic, creating London’s most prominent built fragment of the Ringways-era urban expressway vision. The elevated road provided a high-speed corridor but also intensified criticism about environmental impacts and neighborhood disruption. These experiences strengthened opposition to building more inner-city motorways.
The GLDP inquiry completed its hearings after sitting for nearly two years and considering tens of thousands of objections. Its conclusion set up the government’s decisions on which parts of the plan would proceed, be reshaped, or be rejected. By this point, the Ringways proposals had become politically and financially difficult to sustain in their original form.
The inquiry chair, Frank Layfield QC, delivered a major report to the government after the GLDP inquiry. The report documented the scale of objections and influenced how ministers and the GLC responded to motorway proposals. It helped formalize the move toward prioritizing public transport and away from broad inner-London motorway construction.
Construction of the East Cross Route—a major north–south expressway corridor in east London—was completed. Although designed as part of Ringway 1, it ended up functioning as an isolated high-speed route once other parts of the Motorway Box were not built. The East Cross Route became a lasting example of how partial delivery changed the purpose of Ringways-era roads.
Construction began on parts of the outer ring roads (Ringways 3 and 4), which were later combined into the M25 concept. Unlike the inner Ringways, the outer orbital route faced fewer direct impacts on dense inner-city neighborhoods, making it more politically feasible. This marked the practical pivot from an inner-city “motorway box” to a primarily outer London orbital motorway.
The UK government presented its position on the GLDP inquiry findings to Parliament, highlighting the inquiry’s scale and its recommendations. Debates around the “London Motorway Box” showed that public transport priorities and environmental concerns were increasingly central. This political context accelerated the retreat from the full Ringways program.
As the Ringways program was cut back, planners reshaped the outer-ring projects into a single continuous orbital motorway: the M25. This consolidation replaced earlier ideas of separate outer routes and numbers (including the M16 concept) with one signed route for the London orbital. The change helped align construction toward a clearly defined end goal: a near-complete motorway ring around Greater London.
The first opened section of what would become the M25 ran between South Mimms and Potters Bar (later M25 junctions 23–24). It was initially linked to Ringway 3 planning and was at first associated with the provisional M16 designation. Opening this section showed that, even as inner London motorway plans fell away, the outer orbital road was becoming a reality in stages.
The last remaining gap—between London Colney and South Mimms (junctions 22–23)—opened, allowing the M25 to function as a continuous orbital motorway (working together with the A282 at the Dartford Crossing). The opening symbolized the lasting legacy of Ringways-era thinking: while most inner London expressways were cancelled, the outer ring was delivered. The M25 quickly became heavily used, shaping travel patterns and development around London.
Construction and opening of London's Ringways and the M25 (1966–1986)