#insights

Public transport is the most sustainable, least space-demanding, and safest way to move large amounts of people in urban and metropolitan environments. To evolve towards more sustainable mobility model in cities, public authorities are increasingly adopting restrictive measures on the use of private vehicles, such as urban tolls, low-emission zones, parking restrictions, etc.

However, it is essential that these measures are complemented with a determined commitment to improving public transport systems, so that citizens do not have to resort to them as the last – if not only – resource to be able to carry out their needs and daily trips, but to give them more opportunities to rely on them voluntarily, at will.

How should public transport in cities evolve to achieve this? And how can we contribute to this – or how are we already doing it – from the engineering perspective?

Although it may be obvious, it is first necessary to take a step back and try to reduce transport needs as much as possible, fundamentally through better urban planning. Measures such as, for example, greater interweaving of residential areas with office and service areas or a greater distribution of public equipment can contribute very significantly to this regard.

Turning now to transportation itself, it is essential, first, to have a well-structured network that serves the most demanded origin/destination relationships, with a capacity adequate to demand, maximizing frequencies in peak periods, minimizing travel times, and ensuring maximum punctuality of services at all times.

This requires adequate planning of the network, and the corresponding investments to be able to carry out the necessary actions. The implementation of state-of-the-art traffic control systems, such as CBTC (Communications-based train control) and automated driving, can be of great help in this regard, making it possible to increase frequencies and capacity for a given infrastructure.

Another fundamental aspect to take care of is the user experience. This covers very diverse aspects, from comfort (both in the vehicle and at the station, without forgetting the reservation and payment processes for the trip), to information (which must be accessible, reliable, and permanently updated), the air quality and health, etc.

Going even further, we must think about turning trips into something more, into experiences, transforming spaces (stations, vehicles, transit areas…) and providing complementary services that add value to the user, while improving the model of the operator’s business and therefore the profitability of the system.

It is also necessary to offer – or at least facilitate – door-to-door travel, complementing high-capacity core networks with first- and last-mile capillary services. This can be achieved with the support of other smaller capacity services, on-demand transportation systems, fleets of autonomous vehicles, bicycles, other personal mobility systems…

The necessary mode changes must be able to be carried out in the most fluid way possible. Therefore, the improvement of intermodality must be considered a priority, both from the physical point of view (through interchange stations, parking for bicycles and personal mobility systems, the possibility of loading them on public transport…) and from the point of view of the reservation, information, and payment of the different services, ultimately reaching the paradigm of mobility as a service.

It should not be forgotten either that everything mentioned up to this point must be accessible to all people. It is necessary to adequately address the needs of all users, including – and with special focus on these groups – the elderly, people with disabilities or reduced mobility, people with strollers and children… and, of course, people with greater difficulties to access to online digital services.

Of course, it is also essential to guarantee the safety of transportation systems, in all their aspects: traffic safety, operational safety, personal safety of users at all points of the trip, safety against fire, safety -unfortunately- against terrorist acts… And, because of increasing digitalization and connectivity, cybersecurity, which is in fact already an element of capital importance from the initial stages of the systems design itself.

Although it has already been mentioned at the beginning that public transport is at the forefront of sustainability, it will still have to evolve to be even more sustainable, further reducing its carbon footprint, according to the awareness and growing demands of society in this regard. sense.

To achieve this, progress must be made in the use of ecological materials in infrastructure, such as wood (whether in finishes or enclosures, but also, why not, in structural elements), as well as recycled materials, such as concrete. demolition.

It will also be necessary to continue advancing in terms of energy efficiency, through measures such as the efficient design of power systems, the regeneration of braking energy, the efficient design of the layout of the lines and stations, workshops and depots. , the efficient operation of ventilation and air conditioning systems, the use of dissipated heat… New modeling and simulation technologies, such as BIM (building information modeling), energy models or digital twins are already allowing us great advances in all these subjects from engineering.

Of course, the transition of all traction systems to power with renewable energy sources must be completed, whether electricity (catenary or third rail, batteries or even induction), or also green hydrogen. Going further, more and more progress will have to be made in the integration of renewable generation sources associated with the transport infrastructures themselves, combined with storage systems, smart grids and intelligent management systems that allow optimized management of the whole.

The strengthening and improvement of public transport systems must be carried out without forgetting that these should in no case be a foreign element in the city, but rather a part of it. Therefore, they must be integrated into the urban reality and merged with the rest of its elements in a harmonious way, so that even the citizen who uses them can come to appreciate them as a valuable element of the urban landscape.

A final essential aspect to encourage the use of public transport is to be able to offer the service at the lowest possible prices, so that it is not only more attractive, but also guarantees the right to mobility of all people.

This is being undertaken in many cities through public subsidies. However, to guarantee the economic sustainability of the systems, it is necessary to work on minimizing operating costs, through measures such as driving automation, optimization of maintenance processes, predictive maintenance, the measures themselves. energy efficiency already mentioned above, etc.

But we should not only think about operating costs. To reduce the cost of transportation it is also essential to minimize the first investment costs, and this is a point in which engineering plays a key role. To do this, first, it is necessary to adopt in each case the most appropriate solutions based on demand and the rest of the concurrent factors, from the most expensive underground metro solutions to more economical tram or surface light rail solutions, and others that are even less widespread in many geographical areas, such as monorails or BRT (bus rapid transit).

It is also necessary to advance in standardization, modularization, and prefabrication, as well as in the use of the most appropriate materials for each specific situation and location.

And of course, efforts must be made to optimize solutions during the design phase, through continuous value engineering exercises, given that it is in this phase where the greatest economic savings can be generated. For this, once again, we can count on the invaluable help of new technologies, such as BIM, which allows virtual construction to be carried out and minimize the possibility of errors in execution, system integration techniques, with a key role in projects as complex as those of a metro or tram system are today, or data analytics, of great help both in the design process and, for example, in risk control during construction.

As indicated at the beginning of this article, the necessary improvement in urban planning processes should reduce unnecessary trips, and thus transportation needs. In this sense, it remains to be seen to what extent teleworking, the digitalization of services, remote care and virtual reality will also contribute to this, which will increasingly allow us to carry out a greater number of activities without leaving our home. Who knows, perhaps there will come a time when we end up taking virtual trips in the metaverse, an opportunity for society to continue realizing the value that transportation engineers can bring.