The concept of ridesharing has existed for decades, but big names like Uber and Lyft have pushed the idea further, allowing us to hitch a ride in a private-car instead of a cab.
However, not all these services are real ridesharing, but rather a private taxi service.

Lyft’s distinctive pink moustache was the first branding the company used until 2015. Photo: Wikimedia

“Real ridesharing, like Zimride and BlaBlaCar, match multiple travellers into the same car and each traveller, including the driver, specifies when and where they are going from and to”, explains project researcher Yaoli Wang, from the Department of Infrastructure Engineering, University of Melbourne.
“Even UberPool’s model of sharing rides is rather ridesourcing since the driver does not start with a specified travel destination in mind.”
Despite all the hype, and the commonly accepted benefits for traffic, the environment and the private purse, there are reasons why ridesharing is not as popular as it could be. Mainly because people are reluctant to detour for others, trust strangers, or to share personal space.
Disruptive technologies such as driverless cars carry the potential to change the paradigms for ridesharing. Cost models will change the perceived need for a private car, and mobility will be seen as a service rather than a dependency for a driver.
Ridesharing is the future of urban travel, and has been the focus of study for the Computational Transportation Science group at the University of Melbourne for more than a decade.
A new perspective
Today, Uber’s ad reads “We ask only one question: Where to?”. This is also the question posed by almost every ridesharing application at the moment. But is this really the best question to ask, given all the reluctance to take up ridesharing? It certainly doesn’t address trust or flexibility.
The team at the University of Melbourne is now asking the question: “who do you want to share a ride with?” rather than “who can you share a ride with?”. And a follow-up: “what do you want to do?” rather than “where to?”
Could the answer for mainstream acceptance lie in social networking?
Friends and trust
Busy commuters don’t want to sacrifice too much detour time for a stranger, and many don’t want to share with a stranger at all. It’s these problems that have led to the development of a new ridesharing concept – social network-based ridesharing.

Companies like Uber and Lyft have pushed the concept of ridesharing. Photo: Pexels

Social network-based ridesharing applies preferential matching with ‘friends’ within your social media network, even if this increases travel time when compared to rides with strangers. Meanwhile, the option to share with strangers is not removed, but becomes a fall-back when your preferred matches cannot be found in time.
In this approach, sharing rides with strangers also has the positive potential of building new friendships, introducing people who travel similar routes every day but never say a word to each other and changing their perceptions of sharing space with a stranger. Social network-based ridesharing could change people’s perception of sharing a space with this stranger, thus increasing and broadening their own social network.
Travel budget and flexibility

Another concern is that no one wants to be delayed on their journey or run late. But if commuters stick to pre-existing friendship circles for ridesharing, they could be missing out on those people nearby who share exactly the same route.
This disadvantage is addressed by activity-based ridesharing: a ridesharing strategy that allows you to choose from multiple alternative places to pursue an activity (like shopping or exercising) within your time budget and with the added bonus of increasing your chance of finding a ride.
“Many activities are not limited to one location, even if you had one particular location in mind when requesting a ride. Imagine you want to go the gym; if currently no ride is available for your usual one, you might be happy to get a ride to another branch of the same gym chain,” explains lead researcher Professor Stephan Winter, who works in the Spatial Information Science in the Department of Infrastructure Engineering, University of Melbourne.
What are the next steps?
The two approaches of social network-based ridesharing and activity-based ridesharing can be combined. Collaborative activity-based ridesharing achieves both, matching traveller’s preferences, and profiting from the higher flexibility of activity-based ridesharing.

The next step is making collaborative activity-based ridesharing viable for everyday life. This involves a number of practical challenges, from mechanisms to form and maintain networks in a trustworthy and socially acceptable manner, to managing the technical complexity.
We need good approximation algorithms to cope with the number of potential travellers and the possible destinations. Additionally, there needs to be a focus on local solutions to the rideshare matching problem, aiming to get rid of central platforms (like Uber) altogether.
“Finding an ad-hoc ride requires the vehicle to be nearby – limiting my search to the immediate neighbourhood, using short range communication protocols, instead of relying on a server that is managing all ride opportunities and all rides requested in a city,” says Professor Winter.
Urban mobility as we know it already shows signs of being disrupted – and where it goes from here, with the impact of social media, could see many more of us sharing a ride in the future.