Prevention runs through optimization

written?by Antonio Restuccia

The outbreak of Covid-19 pandemic turned our lives upside down, and the world of transport was not exempted: the collapsing of airlines business, the need to think again about our daily journeys in terms of social distancing are just a few examples.

As predictable, we have witnessed a nose-up in the use of private vehicles, as people are looking for protection inside the “cockpit” of their cars. Luckily enough, ?remote working, whether ?is "smart" or not, ?calms down a little bit ?this invasion of cars.

Furthermore, luck or sadly, not everyone can afford to own a car: for these people, public transport is the only alternative left. Some cities reacted increasing the supply of public transport (higher frequencies, and more spacious vehicles in order to increase the overall capacity), but in too many other places, where budget is not allowing any ?investment, the issue of overcrowded?buses and trains is “sword of Damocles” hanging on those cities.

When we think about the classic 4-step travel model widely used to?represent the mechanisms regulating trips (generation, distribution, modal choice and finally assignment), the temporal dimension is a Cinderella, often left outside. Instead, we have to ask ourselves: when does the trip happen?

An action on transport systems does not involve necessarily changes to infrastructure or services. a low-cost solution could be extending the trip time frame, replacing peak times with gentler hills. By “flattening the curve” (a concept that we are now familiar with) the crowding of public transport (but also road congestion) would benefit greatly.

In this context, it should be pointed out that CUBE Voyager by Bentley System, with its flexibility, allows developing of advanced demand models, capable of optimizing entry times according to the expected load on the public transport network.

The information can then be sent to a ?city or region “mobility management system” with the role of coordinate and regulate all the opening times of production activities, schools and services. A big brother, but in a good way.

?

The CUBE Voyager technological solution

Cube Voyager software can simulate the effects of crowding in Public Transport vehicles, through the use of an ?integrated crowding model that iteratively adjust:

- perceived on-board time (the user perceives a longer travel time when traveling standing up and in situations of overcrowding, compared to when sitting) using specific crowding curves, predefined or created for the specific context.

- waiting time at stops, because in the event of excessive crowding of the arriving vehicle, the user may prefer to wait for the next ride.

?Thanks to the use of the crowding model, CUBE can identify “bottlenecks" and calculate, for each origin-destination pair, the proportion of demand that is unable to reach its destination due to poor capacity of the transport system.

These mechanisms therefore make it possible to overcome the limits of the more basic models, where travel times are ??basically functions of distance and speed, ?and it is assumed that users board on the first service arriving at the stop.

?The crowding model includes a "damping" mechanism of both crowding factors, volumes and waiting times that helps stabilizing the resulting assignments. Since the path choice process is more responsive to cost changes, using a frequency-and-cost model when using crowding provides better convergence, compared to a simpler?frequency-only model.

?Due to the “heuristic” nature of the algorithm, the usual iteration stops criteria (such as relative differences between two iterations, RMSE, maximum number of iterations) do not represent an indication of reached convergence. To overcome this, CUBE provides additional statistics and convergence measures for each iteration that can be analysed by the user.

CUBE therefore allows you to set up and test useful scenarios for the redesign of transport services, to evaluate the increase in sense of comfort and quality, real and perceived, by the passengers.

Get in touch with us to find out more on how to include advanced crowding and demand optimization solutions into your models!

?Book a Free Consultation

Find out how to include advanced crowding and demand optimization solutions into your models. Book a free consultation?using this form?or visit our web site https://www.citieume.com/