How will we ensure that we achieve long-term benefits from any changes
to the way in which capacity is apportioned in our streets post-COVID19?
“There has been for some years, a realisation that the way in which the finite capacity is apportioned in our busy urban streets will need to be reviewed to cope with the ever-increasing demands put on them. As a result, we have seen our streetscape gradually evolving to benefit the increasing number of members of the public who are using active transport modes, such as walking and cycling. In London and other cities in the UK, parts of the road network have seen lanes being removed from use for mixed traffic, and reallocated to provide additional capacity typically to buses, cyclists and pedestrians. It would seem counter-intuitive that reducing the available space to mixed traffic can in fact increase overall capacity, but by encouraging users to switch their mode of transport by providing quality infrastructure to support this, can indeed reap positive results. A single bike lane can transport many more people than a traffic lane, particularly during periods of congestion.
Currently, as we plan for the post-COVID19 world, some of the assumptions we have made over the past few years are now being challenged. One of the biggest is the realisation by many that there is now a hugely reduced need for many to travel to a fixed place of work every day, so that the use of agile working practices will inevitably increase, if not only so that employers can reduce their overhead costs significantly. How this will translate to demand for services by commuters is still open for debate, but it is probably safe to say that the requirements for people to still go to a fixed workplace (even if only on a weekly or monthly basis) will remain. We will therefore need to ensure that workers are able to commute in as safe and efficient manner as possible.
One of the biggest tenets of local authorities to overcome congestion, has been to encourage travellers to use public transport in and around our cities. Passenger numbers on our railways have increased year on year taking commuters in and out of cities, and buses, trams and underground services provide effective means to transport the public within urban areas. However, in the social-distancing era we now find ourselves in, we are currently being encouraged to only use these forms of transport as a matter of last resort. The reasoning for this is because the capacity of all forms of public transit will be conclusively compromised if the need to implement effective social distancing measures endures as is predicted. To counter this impact on the ability to transport the public safely, the use of active transport modes, which consist primarily of walking or cycling, is being promoted. However, it is immediately obvious that, due to the nature of many of our city centres, there will not be sufficient space in our streets to cope with the growing demand for use by Non-Motorised Users (NMUs) to move around by these means whilst still observing the requirements to socially distance from others. There is a real concern that the density of people using our streets, in an attempt to avoid overcrowding on public transport, will instead fall foul of this whilst walking or cycling.
Modelling analysis of the impact that social distancing requirements will have on the capacity available to pedestrians whilst accessing interchange hubs, such as railway stations, has revealed that in many scenarios, it is unlikely to achieve better than a third or quarter of ‘normal’ levels of use without compromising safety. This will therefore be particularly exacerbated at pinch-points, such as road crossings, where queues of users waiting are likely to conflict with other movements and may result in the breakdown of orderly conduct, particularly when the crossing goes green and users scrabble so as not to miss the opportunity to move forward. To overcome this, many city authorities around the world are closing streets to traffic to provide more room to allow users to spread out. To assist in this, some areas are also implementing one-way systems to ease the ability of NMUs to maintain the required distance from others.
Problems though will occur when these busy streams of users encounter bottlenecks, such as flows of conflicting vehicular traffic and are forced to make use of traffic signals or pedestrian crossings. At these pinch points, the pooling of pedestrians and cyclists will inevitably lead to congestion and the likely resultant breakdown in observing social distancing requirements. Anyone who has witnessed busy cycle lane approaches to signals or pedestrian crossings will know that there is already often a problem of users spilling out across footways and traffic lanes, and that this will simply not be acceptable to the public, especially if the number of NMUs increases in response to the move away from public transport.
Across most cities in the UK, traffic systems make use of extensive, sophisticated vehicle detection equipment to optimise the operation of traffic signals across a city. The vehicle detection infrastructure will typically gather data in real-time on the number of vehicles leaving each set of traffic signals, so that the traffic system knows how many vehicles will arrive at the next set of signals.
In this way, it is possible, using the Urban Traffic Control (UTC) system to constantly optimise the operation of the signal infrastructure to adapt to current traffic demands. Most cities use a UTC system called SCOOT which achieves this adaptive form of operation.
However, when it comes to the way in which pedestrians and cyclists interact with these systems it has generally been fairly rudimentary. Currently, most traffic systems only use crude presence detection for pedestrians and cyclists. At signalised pedestrian crossings, a pedestrian push-button is used to register that a user wishes to cross, however, this is a simple input which does not include any other parameters, such as the number of times the button has been pressed, it simply knows that it has either been pressed or not. In a similar vein, where specialist cycle detection is provided at traffic signals, usually only on segregated cycle approaches, these will only register that there is a cycle present and does not account for the level of demand.
The technologies exist to capture the data, using a range of tracking radar and thermal imaging to actively identify NMUs from a background of other modes of transport. These can then provide real-time data sets that include effective classification, count and even trajectory. What is really missing at the moment is flow data for these sets of users, so in a similar way in which SCOOT provides information about the number of vehicles about to arrive at the next set of signals, we could start to use data regarding situations such as the number of people leaving the railway/tube/bus station currently, or who are walking from one set of signals to the next. This type of information for vehicular traffic has often made use of Automatic Number Plate Recognition (ANPR) technology to provide current journey time information from one node to the next, and surprisingly this type of approach can also be used with NMU’s despite their lack of identifying number plates. To achieve this, it is possible to use the unique Bluetooth and WiFi identifying numbers of peoples personal devices to monitor flow conditions of passing users. These types of systems are already widely used to monitor movement in locations like airports and large shopping malls, and can provide detailed information, such as the journey time taken from getting off a plane, walking through an airport through immigration, baggage reclaim and even onward via transit to downtown.
The SCOOT kernel had an item added to it some years ago to make use of a measurement of pedestrian demand to adjust operation of crossing facilities. This uses quite a crude volumetric approximation of the number of people waiting to use a crossing but is the sort of feature which will need to be used more extensively to alter the level of priority and crossing time provided to pedestrian movements. Many modern signalised PUFFIN type crossings also already have detectors to alter timings in response to pedestrians’ progress on the crossing, so this may be an opportunity to review the pre-programmed timings associated with these facilities to further heighten the priority of NMUs over vehicular traffic.
As far as the traffic signals themselves are concerned, these types of requirements are achievable now. Each traffic signal controller uses a site-specific software configuration (or program) to operate, and these can be altered to update the required method of operation achieved at individual sites to tailor their operation and to work with additional equipment.
By use of these types of technologies in our urban areas, it will be possible to not only monitor NMUs in our streets, but to also follow these streams of users through their entire journey including at bus stops, within transit interchanges (such as bus or railway stations) and onward to large offices or attractor destinations such as shopping malls. By using these data sets, it will be possible to not only react to current overcrowding issues, but to also undertake analysis to predict future issues as footfall increases over time.
Reactive interventions could include a broad range of features, not only changing signal timings at crossings, but also disseminating travel information to users via apps and on-street display signs. This would be very important when services do not run as planned so that users can seek alternative routes or revert to working from home and making the trip another day. It might also be possible to allow transit companies to increase service frequency dynamically to cater for numbers of passengers. Proactive interventions are also likely to be required for commuters to pre-book seats on public transport to avoid long queues and the increased journey times that are likely as a result.
So how can disparate data sources be brought together to influence and inform the Intelligent Transport Systems (ITS) which operate our transport networks and offer a pathway for additional stakeholders to gain value from their use? The Urban Traffic Management and Control (UTMC) initiative, launched in the UK by the Department for Transport, sought to use modular systems based on open standards to allow highway authorities to achieve their transport objectives without being constrained by ‘single source’ solutions. Commercial UTMC products benefit from the experience gained from continual technological evolution implementing intelligent smart mobility applications by leveraging the advantages of open standards, allowing equipment and sub-systems from different suppliers to work effectively together. This type of platform allows data to be easily exchanged between different stakeholders, while benefitting the operation of the city at the same time. There is a current and real need to make a significant boost to active transport modes in our urban centres.
In addition to using temporary traffic management features to implement facilities to assist in achieving these goals in the short-term, thought should be given to not only making Transport Planning Assessments of the effectiveness of proposed interventions, but to also support these by deploying suitable technology features to allow dynamic control and critically, monitoring of their operation to be achieved. A substantial investment boost from central government has been announced to assist in achieving this. This might prove to be an effective method to deal with a lack of capital expenditure on traffic systems during the austerity era and allow local authorities to undertake equipment renewals to facilitate the modal shift desires of central government. These types of interventions will also support major environmental improvements to be supported and to maintain the temporary benefits that have been achieved during the course of the pandemic, with reduced emissions and improved air and water qualities being realised very quickly in many cities. There is a real opportunity to regain public urban space away from mixed traffic use to support the greening of our urban environment. Without such a movement, and due to the fact that public transport capacity is now greatly reduced, the result is likely to be a worsening of congestion on our roads, a situation worse than before COVID19.