Modifying your original route while driving: not always a good idea

In: Blog, Nodum news, Road ecology, Safety, Smart Mobility, Traffic management

We all continuously check our GPS to find the quickest routes to our destinations, but can we be sure we actually take the fastest ones? 

Last Christmas, I had to drive from Washington DC to JFK Airport in New York City: My phone estimated 4 hours and 38 minutes at the time of departure through highway I-95. It was peak time in the Christmas season, so I planned and left in advance as I expected more delays than usual. As I moved forward through my route, I started to get some traffic due to accidents and some construction operations on the highway, adding 47 more minutes to my trip. I finally listened to my phone and I took the proposed detour via local roads that would save me some time. What initially seemed to be a good idea, turned to be a never-ending driving seeming experience.

Apparently, everyone took the same detour that I did, so the local roads ended up having heavier traffic than the I-95 route. When I finally arrived at JFK, it took me 5 hours and 42 minutes, 64 minutes extra instead of the original 47-minute delay if proceeded through I-95.

How could this be prevented? It looks like the number of vehicles that chose that alternate route highly exceeded its capacity, generating bigger congestion than the original one in I-95. Longer travel times are more susceptible to changes, as several factors can modify the original time estimation. Nevertheless, this case can be studied from a traffic management point of view to extract conclusions.

Do regular mapping software actually provide the fastest detour?

In general terms, regular mapping software used nowadays comes up with the fastest possible detour at the time the vehicle faces an obstacle. Indeed, the user will always be driving in the quickest path to arrive at his destination, but this path may not be the most suitable one to be proposed as a solution to traffic congestion. Is that detour ready to face the traffic created by hundreds of new vehicles? Will this bypass originate future traffic congestion to adjacent roads? How will this new traffic impact surrounding neighborhoods? Alternate routes shouldn’t be selected as provisional solutions to a problem, they should instead be studied in advance.

Nodum solves this and other problems by applying a different concept to traffic management. All possible detours are previously studied by engineers to guarantee a continuous traffic flux. If the detoured vehicles have a possibility to originate new traffic congestion, this alternative will not be selected by Nodum and a new one will, therefore, be evaluated.

This concept is highly emphasized in roadways under construction with live traffic, where accidents or production activities can generate a higher impact on traffic. The general contractor can use this software to choose which detour will be most efficient in case of a roadway closure, making sure they have enough capacity.

Two statements can be deducted if Nodum was used in my JFK trip: First, its duration would have been surely shorter; and second, all neighbors that were affected by all the hundreds of vehicles blocking their local roads would have experienced a way more peaceful day.

Could “air control towers” be used in highways?

In: Blog, Nodum traffic, Road ecology, Safety, Smart Mobility, Traffic management

Air control towers have achieved full aircraft coordination autonomy since their appearance. Traffic jams and accidents still occur on highways all over the world: is that a consequence of an obsolete roadway traffic management model?


The air transportation example

A total of 100,000 planes fly our skies every day, and 11,000 of them do so simultaneously. These aircraft do not freely travel the airspace, but they follow instead the path of imaginary air highways previously established and ordered according to their direction and flight level. In this way, an optimal air traffic control is achieved, and it guarantees the best plane route by basically following two parameters: the shortest possible distance between departure and arrival, and the aircraft security.

The same thing happens at airports: hundreds of planes take off and land every day in the same location. Thus, a careful management of the air traffic must be achieved in order to ensure the success of every flight. As we already know, the airport control tower is the one responsible for this task, creating hypothetical flight paths for each of the planes. The objective is always to achieve the greatest number of operations in the safest manner.

As seen, there is an existing infrastructure previously created for this transportation method, although it is not a physical one in this case. Any aircraft could objectively choose which “highway” to use by itself, but we all take for granted that the control tower needs to properly coordinate air traffic and guarantee its efficiency and safety.

Air control towers reach an optimal traffic management level

A different model is nowadays used in roadways

This concept is not found in roadways. A physical infrastructure defines all possible routes that vehicles can follow. However, as opposed to air traffic, the roadway does not have a control tower concept directing it all. Each car freely chooses its path through a previously created infrastructure instead. This route election freedom may result in a human error factor causing issues not found in air transportation such as congestion and safety issues (accidents). For this reason, this human error must be minimized, and better coordination of cars must occur to achieve a continuous traffic flux.

Elements for global traffic coordination are already in use such as traffic lights (they give priority among vehicles and other transportation methods), HOV lanes (they filter cars according to the number of people they carry), and toll lanes (they redirect the vehicles to a faster route in exchange for a fee). However, none of these focuses on the individual vehicle; instead, they manage all of them as general traffic. Would a “control tower” work in roadways? A control tower could guide each single vehicle, guaranteeing the effective flow of traffic.

Nowadays, it is kind of hard to think of this basically due to the following reasons: the current difficulty to simultaneously connect all cars, and the current lack of connectivity between vehicle and infrastructure. Luckily, the new automated vehicle industry may give a solution to both problems.

Connected vehicles could bring the solution

Let’s focus on the following example: a group of ants walking in a straight line. We can see them all perfectly aligned, walking at a constant speed and keeping an equal distance between each one of them. They work perfectly as a group thanks to the coordination they have between them. In their case, each ant is provided with antennas that act as receptors and information issuers. These antennas keep the ants connected with one another, and using this information they can stay informed about which route to follow, the proper distance to keep between one another, or any possible danger to be found in their path so they can made a proper alternate detour.

This basic example found in the animal kingdom can be applied to self-driving cars. They are also provided with sensors showing other vehicles’ locations or the appearance of an obstacle. Then, each car will drive their route considering these elements. However, these self-driving cars adapt their path and speed according to the existing traffic conditions. There is no general entity directing them through the best way to follow. This is where the concept of a “control tower” may be very useful to traffic management, as it could detect in advance the existence of an issue in the road, instead of instantly reacting to it once it encountered.

The key will be to figure out how to connect the vehicle’s receptor system with this “control tower” entity so they can speak the same language. In this way, the “control tower” we are talking about would not be a physical element as encountered in the air transportation. It would rather be a centralized software that could direct each car to the optimal path, reaching to create the perfect traffic management system. Then, agencies such as DOTs or highway management companies could work as traffic conductors. This “control tower” concept could redirect automated vehicles to the most suitable route, so the following is guaranteed: an efficient and safe traffic through all highways.