Smarter Cambridge Transport

Can we do better than bus lanes?

The County Council’s view

‘Bus priority’ has come to be used interchangeably with ‘bus lane’ or ‘busway’: the Cambridgeshire Long Term Transport Strategy (November 2014) refers to, “On-line or off-line bus priority measures between the A428 and M11” and “On-line bus priority measures between the M11 and Queens Road.” This is unfortunate because ‘bus priority’ covers a number of techniques besides segregated roadway:

  • signal priority (where the lights change as a bus approaches)
  • filtered permeability (where buses have exclusive access through control points)
  • gating (where traffic is held in a queue that buses can circumvent)

By narrowing strategy to ‘bus priority’, and then even more narrowly to bus lanes, we are in danger of losing sight of what we are trying to achieve: to increase bus patronage by people who currently drive into and around the city.

The Transport Strategy for Cambridge and South Cambridgeshire – Transport Strategy and High Level Programme (March 2014), from which much of the City Deal programme is drawn, states:

A major impediment to the reliability of and the further increase in usage of bus services within and into Cambridge is the delay experienced by buses due to congestion caused by general vehicular traffic in the city. With the growth that is planned for the city, this impediment must be removed if the bus network is to become the mode of choice for many more journeys. A step change in the quality, availability and reliability of bus services within the city is needed. To achieve this, comprehensive bus priority is required over time on main routes used by buses, including:

  • Milton Road
  • Newmarket Road
  • Fendon Road / Mowbray Road / Perne Road / Brooks Road / Barnwell Road
  • Mill Road
  • Gonville Place / East Road / Elizabeth Way
  • Hills Road
  • Madingley Road
  • Histon Road

The key assumption here, that congestion is ‘a major impediment to the … further increase in usage of bus services,’ needs to be tested. After all, congestion does not disadvantage bus passengers relative to car drivers: it delays and frustrates both equally.

The unstated purpose in trying to give buses an advantage when they meet congestion is to offset disadvantages of bus travel. This begs two questions:

  1. How much of an advantage do bus lanes provide?
  2. What are the disadvantages of bus travel, and how can we address those directly?

The case for bus lanes

‘Common sense’ intuition says that bus lanes can make a large difference to bus journey times, and make taking the bus significantly more attractive to car drivers.

How much faster?

If cars are moving at just 5mph, then a bus travelling at 30mph along a mile of uninterrupted bus lane will be 10 minutes faster. But is that ‘best case scenario’ typical? Two detailed professional studies of bus lanes concluded that it isn’t.

The most thorough study of bus priority schemes, conducted by TRL (the country’s leading transport research company) in 1999, drew this conclusion (see Appendix):

The overall picture is that major bus priority schemes have mixed effects, there are successful and disappointing examples in those surveyed, but on a whole they are successful to some degree.

In 2014, Mott Macdonald (the company behind the Cambridge Access Study) delivered a report after all bus lanes in Liverpool were suspended for nine months (see Appendix):

Evidence shows that these bus lanes were generally only providing minor benefits to bus journey times, and that whilst reliability was adversely affected in some cases, more significant bus delay and unreliability was typically the result of other factors….

Examples of bus lanes that proved to be ineffective, or which had an unacceptably detrimental effect on other traffic (see the cases of Truro and the M4 in the Appendix), suggest that modelling how people will behave once a bus lane is opened is subject to a wide range of uncertainty. Modelling can only be as good as the data used. In Cambridge we do not have detailed journey data (with start and end points), only traffic counts at a few locations, so modelling changes of behaviour and net benefits is really only formalised guesswork.

How much more attractive?

Is saving five minutes on the morning commute the critical determinant in whether someone drives or takes the bus? Robust research indicates not. For instance, the TRL study referred to at the start, drew this conclusion:

Patronage data from the schemes reviewed suggest the modest improvements in bus journey times achieved by the priority schemes are unlikely to loosen people’s attachment to the car and create a significant transfer from private to public transport.

The reasons are twofold:

  1. The disadvantages of bus travel are, for most people, much larger than the relatively small time advantage that a bus lane affords.
  2. Drivers are not actively seeking an alternative mode of travel.

What would make bus travel more attractive?

This section has now been developed into a paper on buses.

Reduce total journey time & improve reliability

We must consider the entire journey, door to door, not just the time spent sitting on a bus.


The journey to and from a bus stop, and the wait there, is often discounted by those who don’t use buses. But the time, convenience, comfort and safety (real and perceived) of this part of the journey is a key part of the (potential) bus user’s experience.

  • Provide direct and safe (i.e. well-lit and open) walking routes to bus stops and hubs, including pedestrian crossings of any non-residential roads.
  • Provide safe cycling routes to bus stops and hubs.

Having to change to another service en route can add significantly to the total journey time, especially if the change has to be made in the city centre, or the connecting service runs infrequently.

  • Run services along circular routes, serving more destinations. (This has the added benefit of minimising dwell time in the city centre, reducing pollution and freeing up space at Drummer Street bus station.)
  • Schedule interchanges to other destinations at suburban hubs (such as park-and-ride sites), obviating the need to travel into the city centre to make a connection.


Buses typically follow an indirect route in order to pass close to as many homes and amenities as possible, lengthening the journey time significantly.

  • Run more express (limited stop) services along direct routes.


Each stop can add minutes to the journey time, often unpredictably. Unloading can hold up loading, especially when the bus has only one door. People paying with cash, or needing assistance or information from the driver can add delay.

  • Require bus operators, through Quality Bus Partnership agreements, to implement alternatives to cash payment (which Transport for London phased out in 2013).
  • Encourage bus operators to use two-door buses, to provide faster unloading and loading at busy stops. (CCTV on the exit door can be used to detect fare dodgers.)

A stopped bus can delay other buses. This is especially true in a bus lane at peak times, when the main carriageway is densely packed, providing little opportunity for the bus behind to overtake.


Congestion typically lengthens journey times at peak times, but it can add considerable uncertainty to journey times at any time of day.

As argued in our papers on Smart Traffic Management and Inbound Flow Control, there are techniques that may be highly effective at reducing congestion and pollution in the city, without severely inconveniencing other motor vehicles, and without losing green space within the city:

  • Optimise traffic light sequencing to facilitate free flow of all traffic, and manage the impact of traffic incidents efficiently.
  • Implement bus priority at all junctions, to minimise the wait time for buses at traffic lights.
  • Use Inbound Flow Control to restrain peak traffic flow into the city on radial routes. The TRL study mentioned above explicitly recommends this (‘queue relocation’ – see conclusions 5, 6 and 7 republished in the Appendix). We believe that, combined with other measures, Smart Traffic Management and Inbound Flow Control would render bus lanes unnecessary. But even if that turned out not to be the case, it would be an effective complement to bus lanes.

Parked or unloading vehicles obstructing the carriageway can create significant delays.

  • Ban parking, waiting and loading during peak hours, and enforce infractions promptly.

Turning vehicles can block a carriageway while they wait for a gap in the oncoming traffic.

  • Limit access to and from side roads, thereby reducing the number of vehicle manoeuvres that will hold up buses.

Impatient or unobservant drivers can prevent a bus from pulling out from a stop.

  • Consider introducing a by-law to make it an offence for a road user to begin to overtake a bus that is indicating to pull out.

Cyclists, typically travelling at around 10mph, can hold up buses. This can be a particular problem when both are using a bus lane: at peak times, when the main carriageway is densely packed, the bus driver will struggle to overtake cyclists safely.

  • Provide segregated cycle paths and ‘floating’ bus stops to remove conflict between buses and cycles.

Enhance safety, convenience and comfort

Safety & comfort

  • Ensure people are safe, and feel safe, whatever time of day they are travelling: good lighting and clear approach paths are a must at all bus stops.
  • Install shelters at all bus stops. (Amazingly Cambourne has just two bus shelters: this is Britain, not Barbados!)
  • At travel hubs (rural and urban), provide a heated waiting room, toilets, parking, and set-down/pick-up spaces. The inclusion of a retail outlet (selling drinks, snacks and home essentials), a parcel collection point, and WiFi would add considerably to their attraction.
  • Provide secure cycle parking at all bus stops, plus shelters and secure lockers at hubs.
  • Offer free WiFi on board buses (as on the Guided Busway and X13), allowing people to communicate with colleagues and friends without relying on patchy rural mobile coverage (which would be an advantage over driving).
  • Ensure bus seats, floors and windows are clean.
  • Ensure bus shelters are in good repair.
  • Make it easy to stow luggage, shopping and push chairs on buses.
  • Use buses that are quiet and low-polluting. (The City Council is working with bus operators to phase in diesel-electric hybrid buses over the next ten years, which will bring about a dramatic improvement in air quality in the city.)

Journey planning

Being able to plan a journey easily, without consulting timetables and different maps is what the SatNav generation expect.

  • Under the umbrella of the Smart Cambridgeshire programme, provide a regional journey planner that includes all public transport services, cycle and walking routes, and information about community transport and taxi services.
  • Provide access to the journey planner via a downloadable app, the web and at kiosks at transport hubs.
  • Provide accurate and reliable live timetable information at bus stops and online.
  • Aboard the bus, provide a visual countdown to the next stop, what amenities the stop serves, and what transport connections are available; and provide audio cues for the visually impaired.

Pricing & ticketing

  • Encourage bus operators to offer better value single and return tickets for short journeys and for journeys that require a change of bus.
  • Require operators to publish all ticket prices in a user-friendly format.
  • Facilitate the introduction of multi-operator ticketing for travel on all public transport and parking at park-and-ride sites, making buying a ticket quick and painless.

What would make people choose the bus?

Just providing a good alternative is not enough to change people’s minds: after all that’s why multinationals spend billions on advertising, market research and focus groups.

Once someone has made a decision (e.g. to drive to work), she typically does not continually re-evaluate it; instead confirmation bias takes over, a well-studied psychological phenomenon that almost everyone will recognise in themselves: we pay selective attention to evidence that supports our decision, and ignore evidence to the contrary.

So if a driver sees the bus overtake her in the bus lane, she is unlikely to register it as evidence that she has made the wrong decision to drive. (In fact she’s more likely to feel angry that she could be moving faster if only the bus lane were available to all vehicles.) But when she sees the bus snarled up in congestion at the end of the bus lane, or she overtakes it at a bus stop, that will reinforce her confidence that driving was the right decision.

The most successful efforts to change people’s travel habits involve detailed research, consultation and education/marketing. If we can help people at a point in their life when they are making travel choices, for instance, just after they’ve moved house or changed job, that’s when we can have the greatest chance of persuading them to choose public transport. Travel for Cambridgeshire and Sustrans already lead the way in this kind of work, and the City Deal should seek ways to provide financial assistance.

Research & consultation

Some of the questions we should be asking of a wide range of people include:

  • Why do you choose to drive rather than take the bus?
  • What needs to change for you to revisit your choice?
  • Rank a list of disadvantages of bus travel in order of importance.
  • If you previously drove and now take the bus, what made you change your mind?
  • If you previously took the bus and now drive, what made you change your mind?
  • What do you think you will always use/need a car for?
  • Would you like to be able to manage without a car (or with one less car)?

With better understanding of people’s needs and priorities, we can prioritise measures to enhance the attractiveness of bus travel, and we can tailor our education/marketing messages to what we know people are most receptive to.


Councils need to promote alternative transport options and the journey planner (once developed) continuously, not just with occasional campaigns. Partners should include:

  • Public transport operators
  • Estate agents (a welcome pack for new home owners/renters)
  • Parish councils
  • Residents associations


We are not claiming that bus lanes are always ineffective, only that their benefit is typically marginal, difficult to predict reliably from theoretical modelling, and not necessarily relevant to why people choose to drive rather than take the bus.

A bus lane can, at best, save a few minutes on a relatively short part of an entire journey. Door to door, taking the bus will always have time penalties compared with driving; focusing too closely on beating cars for a small part of the journey misses other ways in which buses can be made more attractive.

There is a wealth of measures to enhance the attractiveness of bus travel. These can be implemented or trialled relatively cheaply and quickly, and they are all likely to be more cost-effective, sustainable, and easier to trial than widening city roads.

Only if those measures fail to deliver a significant modal shift, and if modelling with high quality data provides a very high degree of confidence that bus lanes will achieve that shift, only then should we contemplate taking urban green space or green field land to create new road capacity.

The urgency to spend the first £100m of City Deal money is creating a dangerous pressure to deliver something expensive quickly. Bus lanes are not a good candidate, for all of the above reasons.

Appendix: relevant research

TRL study of bus priority schemes

TRL conducted a very detailed study in 1999, A comparative assessment of major bus priority schemes in Great Britain. It covers ten cities, including Cambridge (Milton Road). Its conclusions in full are as follows:

  1. The data used to evaluate schemes must, as far as possible, reflect the average road conditions, minimising the effects of seasonal variations, roadworks, weather conditions, and abnormal traffic flows. Elements of variation can be reduced by careful planning but to ensure the data reflects average traffic condition it should be collected over several days. ‘Keeping Buses Moving’ offers some advice on what items should be monitored periodically, but this advice needs to be supplemented by guidance on journey time data collection techniques and the amount of data required to obtain statistically significant results.
  2. If models are to be used to test new designs before they are executed, careful attention needs to be paid to the reallocation of road space, alterations to signal staging and to acquiring accurate and appropriate traffic data, which must take account of the numbers, speeds and stopping times of buses.
  3. Schemes should be kept as simple as possible, and more consideration should be given to separating bus and other traffic movements, especially at junctions.
  4. The correct synchronisation of signals along the route is essential. This can be achieved most effectively via an adaptive method of traffic control such as SCOOT or MOVA. These systems have the added advantage of being able to incorporate bus priority components into the system via selective detection.
  5. If queuing space along the route is going to be significantly reduced by the introduction of bus lanes, it is important that traffic queues are relocated upstream of the scheme. This avoids queues building up alongside and beyond the bus lanes so reducing the possibility of exit-blocking upstream junctions and delaying buses before they enter the scheme.
  6. If traffic queues are relocated, there must be enough spare capacity upstream of the holding signals to accommodate the number of vehicles and (if necessary) provide a priority lane for buses to bypass these relocated vehicles.
  7. Effective queue location can only occur if links downstream of the holding signals can be monitored continuously (i.e. the need for an adaptive method of traffic control). This would allow the capacity of junctions along the priority route to be maintained while ensuring queues do not extend upstream of the bus lane.
  8. Where bus priority schemes provide opportunities for reduced bus journey times, service schedules must be adjusted accordingly to achieve maximum benefit.
  9. If traffic diverts from the priority route it is important that the alternative routes are suitable for the increase in demand (i.e. not residential areas or other routes heavily used by other bus routes). Traffic should be discouraged from diverting around sections of the priority route and rejoining further along. This can be achieved by making all major junctions along the priority route, signal controlled. This would allow the majority of the green-time to be allocated to the priority route, making the detour less appealing. Traffic can also be prevented from ‘rat running’ through residential areas by banning certain turning movements onto the priority route. The introduction of traffic-calming schemes may also make ‘short cuts’ less appealing.
  10. Patronage data from the schemes reviewed suggest the modest improvements in bus journey times achieved by the priority schemes are unlikely to loosen people’s attachment to the car and create a significant transfer from private to public transport. A combination of bus priority and P&R may have more success, but not enough to reduce road congestion.
  11. Recently, however, schemes that introduce a package of measures, for example under the new Quality Partnership agreements, seem to be having more success at encouraging bus travel. Several such schemes have reported quite significant increases in patronage over relatively short periods (Leeds, Birmingham). Within this approach bus priority is a vital component, both in terms of perceptions and gaining agreement between operators and Local Authorities.
  12. After the scheme has opened, further monitoring is required to ensure that each element of the scheme is working effectively under the new traffic regime. This may require minor adjustments to both the scheme and supporting traffic management measures.
  13. The overall picture is that major bus priority schemes have mixed effects, there are successful and disappointing examples in those surveyed, but on a whole they are successful to some degree.

The extract above is © Transport Research Laboratory 1999, published with permission of TRL.

Mott MacDonald study of bus lanes in Liverpool

Liverpool City Council suspended all bus lanes in Liverpool on 21st October 2013 for a nine-month trial period. Mott MacDonald was appointed to undertake a detailed assessment study of the impacts, and a review of transport issues and opportunities along three of the key radial bus corridors into the city centre. (The complete report may be downloaded from

The key conclusion of the report for each of the three transport corridors studied is that:

Evidence shows that these bus lanes were generally only providing minor benefits to bus journey times, and that whilst reliability was adversely affected in some cases, more significant bus delay and unreliability was typically the result of other factors….

Examples of ‘other factors’ include:

  • negotiating the city centre;
  • congestion at junctions and pinch points;
  • obstructive parking and loading;
  • bus passengers purchasing their ticket with cash, increasing stop dwell time;
  • buses pulling in at lay-by stops being unable to access back into the carriageway;
  • traffic signals failing to provide enough time for buses to get through junctions;
  • localised congestion at school drop-off and pick-up times;
  • turning traffic blocking through movements.

The report recommended the removal of twenty-two of the city’s twenty-six bus lanes, “and that alternative traffic management measures are introduced which better address the identified issues for all transport users.” Suggestions, which could equally apply in Cambridge, include:

  1. Expand bus-detection system on the approaches to signal junctions, to prioritise their movement through the intersections.
  2. Improve traffic-signal infrastructure along the corridor to benefit capacity throughput and coordinate with other nearby signal junctions, particularly at noted pinch points.
  3. Introduce measures to more effectively promote the safe movement of pedestrians and cyclists, including improvements to road-crossing facilities.
  4. Formally designate on-street parking bays and loading bays, where these will not remove required capacity from traffic lanes and can provide an attractive alternative to illegal parking in more sensitive locations.
  5. Better enforce waiting and loading restrictions – manually or electronically – particularly around junctions.
  6. Demarcate turning lanes better, to help reduce the likelihood of turning vehicles blocking through movements.
  7. Undertake a more detailed review of accidents at hot spots.
  8. Review the location and arrangement of bus stops and waiting facilities to ensure that they are optimal.

In summary, the report says, “These measures focus on addressing key transport issues along the corridor, and will be to the benefit all users whilst also promoting consistent journey times for buses.”

Removal of bus lane in Truro

A bus on Tregolls Road in Truro, serving a park-and-ride site, was scrapped in November 2015, just three weeks after it opened (news story). Bert Biscoe, Cornwall Council’s cabinet member for transport, said, “It is clear that the bus lane has not achieved what it was intended to, and has reversed the improvements of the junctions and the park-and-ride. The Council’s engineers have gathered data from cameras and sensors as well as from road users. The delays caused by the bus lane are counter-productive. We are not achieving a better balanced flow or offering bus users any benefit. On this basis it is clear that this final part of a complex scheme needs to go.”

This demonstrates how far off modelling can be, even in 2015. Committing tens of millions of pounds of capital investment to a new bus lane or busway on the basis of traffic models is far riskier than some experts are willing to admit.

Removal of bus lane on the M4

We include this only because the City Deal Board is contemplating bus priority measures along the M11 between junctions 11 and 13.

In considering whether to revoke the Traffic Order governing the bus lane on the M4, the Secretary of State for Transport found “no evidence that the bus lane has produced a modal shift to more sustainable modes.” The letter may be found here.

Edward Leigh

Edward Leigh is the leader of Smarter Cambridge Transport, chair and independent co-opted member of the Cambridgeshire Police and Crime Panel, chair of the South Petersfield Residents Association, business owner, consultant, and occasional blogger about making the world and Cambridge a better place to live.


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  • The idea of bus lanes is fine but when they seriously delay the rest of the traffic as on Newmarket Road everyone else suffers, including pedestrians with increased pollution. There is no earthly reason why cars cannot use the bus lane from the bridge onwards if they turn off at the next junction into B&Q or the retail park.
    The one farther out needs to be curtailed as the traffic waiting to turn up towards Fen Ditton holds up everyone else. In short the current scheme causes more problems than it solves

  • This is a terrible piece of transport policy. Bus lanes are a fantastic way to improve urban sustainable transport capacity.

    The fundamental point is that buses are the most effictive use of limited road space capacity. A double decker bus typically takes the space of the equivalent of only two cars yet has the ability to carry over 80 passengers, compared to a maximum of 10 passengers in one car. The benefit of those few seconds saved matter over a bus network, and provide a much better economic boost than if given to a private car. KPMG research shows that for every pound spent on bus priority, the economy gains £3.32 in benefit.

    Modal shift from private to public and active transport is a boon to creating vibrant cities. Increasing bus use relieves congestion, increases capacity and reduces air pollution. It enables more sections of society to be ablke to particpate especially older, poorer and disabled people.

    I would suggest you actually look at urban transport mobility, than misguidedly quote a few biased pieces of research in support of your bias against bus lanes. In London the singularly mpst impressive transport policy achievement was a doubling of bus passenger journeys to over 4 billion a year between 1990 and 2014. This was partially achieve through concerted investment in bus priority which ensured that reliability reached it best ever levels in 2014 /15.

    If you were interested in ensuring that the city deal money is spent on ensuring economic growth, reduced congestion, improved air quality and increased access for all to economic growth I could not think of anything better to spend it on than installing bus lanes.

    • I have to wonder if you actually read the paper as almost every point you make misses the mark. You also fell into a trap described in the very first sentence, of confusing ‘bus priority’ with bus lanes.

      Nothing in the article denies the space-efficiency of buses over cars, nor that local authorities should be endeavouring to achieve modal shift from private cars to public and active transport alternatives.

      The sources quoted, TRL and Mott MacDonald reports, can hardly be described as ‘biased pieces of research’. Please cite reputable research that demonstrates statistically significant modal shift resulting from installing bus lanes and we will review and incorporate it into this paper.

      London between 1990 and 2014 does not provide clear evidence one way or another about bus lanes: in that time the city introduced congestion charging and invested massively in new buses, better route and service information, simplified pricing, contactless payments, and a strong price incentive to use buses rather than the Tube. It should be noted that bus ridership is now in decline in London, in part because increased congestion is leading to reduced service reliability – which bus lanes cannot fix:

      That you ‘could not think of anything better … than … bus lanes’ betrays both a lack of imagination and a curious hubris that, because YOU cannot think of anything better, there IS nothing better. Maybe take a look at our paper on Inbound Flow Control?

  • An interesting exchange between David Field & Edward Leigh. The former has the experience of bus priority schemes in London, the latter experience of the complexity of a growing dynamic city with a very different travel to work profile and an urgent need to resolve issues concerning peak hour congestion.
    The camel has a valuable function in travel across the desert but has evident limitations in the Antarctic. There is frankly no common ground; for now Edward is proposing an integrated set of measures that will give Cambridge a healthier city centre and better travel to work choices. His cause is worthy and his direction near perfect and precise. I wish David well in his endeavours in the capital where the bus indeed is part of a valued transport system for and by us all. Oh those bendy buses; how much we regret their demise.

  • […] The benefits of bus lanes have been consistently overstated by council officers. Real-world time savings are less than one minute per kilometre of bus lane, confirmed in the City Deal consultants’ modelling predictions, a bus industry lobby group’s report on The Impact of Congestion on Bus Passengers, and other studies referenced in our paper on Can we do better than bus lanes? […]

  • Looking for evidence as to how “offset bus lanes” affect road safety (issues such as unloading passengers safely when traffic incidents occur) I came across this excellent report.

    Can you help me locate information on kerbside versus offset bus lane studies?

    When I get time I will add to your comments, I am seriously concerned that people who take a biggoted view on bus lanes are obstructing our getting the best out of them … we have local lane that is crucifying traffic (including buses) simply because they were seen as a panacea and no effort was put into managing the implications of a reduction in road space to other users. It should have been a benefit.