£230M+ passenger time savings: How London uses CitySwift to manage bus performance across the city

At over 650 routes, 9,000 buses and 5M+ daily passengers, London's bus network is one of the most complex in the world. Behind every route review and every data point is the same question: is the service getting better for the people depending on it? Managing performance at that scale means managing multiple operator relationships, hundreds of timetables, and a road environment that never stops changing. The one thing that had been missing was a shared foundation: authority and operators working from the same performance data, making decisions together.

In 2024, Transport for London (TfL) and London’s operators partnered with CitySwift to build that shared foundation across its entire network. Within 14 months, the results demonstrated what becomes possible when authority and operators control the timetable together.

Siloed data, slow reviews, and a reactive network

TfL's Performance team is responsible for identifying and resolving inefficiencies across hundreds of bus routes, in collaboration with operators. Before CitySwift, this work relied heavily on manual data gathering and time-consuming analysis, creating three compounding problems:

• Reviews were slow and resource-intensive: Route analysis was time-consuming, limiting how many routes could be assessed at any given time. The team could respond to problems that had already surfaced, but could not proactively identify where the network was drifting before passengers felt it.
• Authority and operators were working from different data: TfL and London’s operators had access to the same underlying data, but no shared platform to act on it together. Performance conversations were slowed by data discrepancies. Decisions that should have been straightforward were slow and drawn out.
• Financial decisions lacked a defensible evidence base: As a public body, TfL must demonstrate value for money across its network spend. Identifying where to reduce costs without compromising reliability for passengers, and making those decisions in a way that could withstand scrutiny, was not possible with the tools available.

With the right shared performance platform, TfL and London’s operators could move from responding to problems to getting ahead of them together.

Performance management at scale

CitySwift deployed its full solution across TfL and the entire London operator network in just 6 weeks, including system training, bringing authority and operators onto a single shared platform for the first time across three core areas:

• Data-driven runtime optimisation and simulation: Using GPS and schedule data, CitySwift surfaces optimisation opportunities and simulates their likely impact before any change is implemented. The Performance team can review routes faster and with greater confidence. Operators have the evidence they need to act. Changes are validated before they reach the road, and before passengers feel the consequences of getting them wrong.
• A shared single source of truth: For the first time, TfL and London’s operators are working from the same data to identify performance issues, agree on interventions, and establish shared accountability for outcomes. CitySwift provides the evidence base for disruption claims and infrastructure-related schedule changes, replacing disputed numbers with a single auditable source both sides trust.
• A proactive network audit tool: A review of TfL's 365 High Frequency (Excess Wait Time controlled) routes identified over 100 optimisation opportunities, shifting TfL's approach from reactive problem-solving to proactive, data-led network management and catching issues before they compound into a worse passenger experience.

The rollout was structured across four phases covering TfL and all operator partners. As of summer 2026, nearly 200 users were actively using the platform across the authority and its network.

Before Cityswift

• Route reviews manual and time-consuming, limiting how many could be done
• No shared platform between authority and operators; data siloed across teams
• Difficult to quantify the financial impact of route changes before implementing
• Network analysis reactive, responding to problems after they surfaced
• Performance accountability fragmented across authority and operator teams

After Cityswift

• Over 40% of the entire London network reviewed in 14 months
• TfL and all operators on a shared platform, with regular collaborative reviews
• Simulations show the impact of changes before they go live
• Proactive network audits to surface optimisation opportunities
• Shared accountability for outcomes established for the first time

“For the first time, TfL and operators are working from the same data, making decisions together rather than in silos. CitySwift has fundamentally changed how we manage performance across the network.”

— Nick Owen, Head of Performance Delivery, Transport for London

Delivering measurable results for London

The partnership started with three goals: faster analysis, measurable financial contribution, and genuine collaboration between authority and operators. By summer 2026, across approximately 250 route optimisations, CitySwift delivered measurable operational gains, and, working jointly with the authority and operators, built a rigorous methodology to prove the financial and social value behind them.

Operational impact:

• Over 40% of the network reviewed in 14 months
• 1.5% reduction in customer journey times on optimised routes, equating to 27 seconds on every trip
• 200 routes improved at no cost through data-led performance gains
• 50 routes where data confirmed no intervention was required
• 50% reduction in route review process time

Tracking the value that matters:

TfL and CitySwift built a joint measurement framework so that reported value could withstand scrutiny; separating hard cash savings from modelled and passenger benefits, rather than blending them into one headline number.

Using this measurement framework, it’s expected that passengers will save £230M+ in journey times across the full 3 year contract. This reflects the cumulative minutes that will be saved across all journeys on optimised routes, valued using the Department for Transport's standard methodology for appraising transport benefits.

What comes next

CitySwift, TfL and London’s operators are focused on deepening the platform's impact across the whole network:

• Scaling the measurement framework: As more schemes accumulate 6+ months of on-the-road data, the evidence base will expand across the network — with cost savings, demand impact, and passenger time saved all tracked on the same consistent basis.
• Timetable validation: Adding CitySwift's simulations as a validation input for minimum performance standard-setting, strengthening the evidence base that underpins authority-operator conversations before contracts are agreed.

Both developments reflect the same direction: moving from a platform that explains what happened to one that shapes what will happen, giving the authority and operators the confidence to control the timetable, not just measure it. Every optimisation, every shared decision, every route review leads to the same place: a service that shows up when it says it will, for the millions of people depending on it every day.