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Exploring New Trails in Daily Mobility

The transportation offer around you influences in many ways how you move on a daily basis, affecting what you do and who you meet. Too often, your mobility options are limited to using a costly car or riding less flexible transit. By changing other driver’s trips passing near you into a potential transport service, carpooling allows you to explore new opportunities in your daily life, at a fairer price.

It’s late in the afternoon and friends invite you for dinner.

They live 10 min away, so you quickly accept, hop on your car or catch your local bus and meet them in no time. Easy.

Now, let’s say your friends live 20 minutes from your place. You would probably still go, but the hop might be a less prompt.

What about 30 minutes? You might start thinking. Do you often have the chance to see those friends? How much do you really feel like having dinner outside?

You would probably still hesitate at 40 min, but as the distance increases, the chance of refusing grows. If they live 2 hours from your place, you will likely, very politely, decline the invitation.

Finding your limit

Somewhere in your subconscious lays a limit separating “close enough” from “too far”. This mental limit defines where you move on a daily basis, what we might call your “daily territory”: a space that contains the shops you spent your money on, the places you meet your friends at, and the streets you walk in.

As important is it might be, deciding exactly where this limit is from your home is far from trivial. Intuitively, this limit looks quite flexible: it depends on time, personal choices and circumstances. This limit wouldn’t be the same if you are a young architect in a city or an old professor in a village, you would think.

Yet, when researchers from different fields looked into it, they found some kind of constant, called Marchetti’s Constant: throughout history, humans have settled in areas where they could reach the other side easily — and easily means 30 minutes in most cases. As soon as somewhere is more than 30 minutes away from you, it becomes somewhere else. This is why villages are often 5 km apart — as villagers are working in fields within 30 minutes from the village centre. This is also why cities only started to grow with the advent of the train or the car — faster transports means longer distances in 30 minutes.

If this seems surprisingly constant to you, consider for a moment your commute time. Even if it is influenced in many ways by housing and economic constraints, travel time to work casts an important light on your daily territory. Like a compass, your commute is your basic daily movement, setting the standard for all your trips.

Well, no matter where you live, there is a high chance that your commute time is around 30min. If you look a daily commute in France for instance, as shown on the map below, you’ll see that most French workers take between 20 minutes and 30 minutes to go to work (a bit more time in big cities due to traffic jams).

Average commute time per agglomeration of communes (EPCI) in France
Average commute time per agglomeration of communes (EPCI) in France — source Observatoire des Territoires

Tell me your transportation and I’ll tell you where you move

If, like most French commuters, 30 minutes is indeed your mental limit, what would your daily territory look like?

If this exercise seems hard to you, remember that you probably have already done it. During the pandemic, many countries decided to restrain our movement to fight the spread of the Covid-19. In the case of France, the government decided on a very clear limit, 1km, and maps like this allowed you to have a very precise image of where you could move.

1km radius around rue Ampère in Massy — source Cascoronavirus

Your daily territory is unlikely to be as clear, but it’s worth wondering how it could look on paper. Unlike on the area above, your daily territory is not define by distance but by time, a 30 minutes circle around your home.

But this can mean very different things depending on which transport you use. As your mode of transport defines how far you can go in 30 minutes, it defines where you can move.

Let’s say you live in Massy, south of Paris, close to the Massy-Palaiseau train. station.

If you move around walking, your map would pretty much look like a circle of 2,5km around your house, as on the image on the left below. Similarly if you’re biking, you can go anywhere that is within 10km from your place.

Places that you can reach in 30min from Massy-Palaiseau by walking (left) or biking (right) — source TravelTime app

If, on the other hand, you own a car, it will be much bigger: an area extending 25km around your home and even beyond if you use the freeways.

Finally, if you want to use public transport, your map will be in-between: extended along the RER (B & C) and metro lines, but empty where there are no transit lines.

Places that you can reach in 30min from Massy-Palaiseau by driving (left) or transit (right) — source TravelTime app

The differences are quite significant and show how much transport is fundamental, influencing where you can go easily and what you have access to. Unsurprisingly, the car gives you the biggest area, by far. Yet, this clear advantage drags a long list of known drawbacks.

For one thing, cars are not safe. Not only do they contribute to global warming more than any other transport, but they also detrimental to humans: in France, cars kill around 40,000 people from air pollution and 2,500 people by road accidents per year.

On the other hand, cars are extremely costly. Cars block each other on routes that can’t welcome them all, leading to unnecessary traffic jams. In total, French workers lose around 23 hours per year in congestion (65 hours in Paris), costing more than 2 billion € to the French economy.

Finally, cars are a heavy burden on the driver’s wallet: on average it costs more than 4,000€ per year, more than 6 times as much as public transport. Between the purchase of the vehicle, the insurance, the maintenance, and the increasing price of oil, the car represents an increasing part of the drivers’ budget.

Taking the cost and congestion into account, the car is not as flexible as the map would make us think.

In comparison, public transport is more accessible and efficient, moving around a lot of people at a low price, both for your wallet and for the environment.Yet, it is constrained spatially by the trajectory of the lines, necessarily rigid in time. If you want to travel between areas that are not directly connected by public transport, it will likely take you a lot of time and energy to make the trip.

Such trips are not hard to find, even in areas with dense public transport coverage like Ile-de-France.

Let’s say you want to go Boulogne in the west of Paris, but still live in Massy. Google Maps tells you that it would take you 22 minutes by car to reach Boulogne, so under your 30 minutes limit.

Google Maps search made in December 2021 — from 1 rue ampere in Massy to Pote de Saint Cloud station in Boulogne

But what if you can’t use a car? By public transport, it would now take you 1h to travel, as you will have to take 2 trains and change in Paris, not at all on the way.

What are your other options then?

Creating a new path

Well, if you look a bit more closely at the screen, Google Maps suggest something new, an option that would only take 22 min for the cost of the train: carpooling.

By matching you with drivers willing to share their car, carpooling gives you the time and convenience of the car, at a fairer price.

Carpooling might not be a solution just to go to Boulogne. No matter where do your friends live, if they live within 30 minutes of your place, there’s a good chance that you can go join them by carpooling.

On the map below, you can see all the carpools available this week on the carpooling app BlaBlaCar Daily. As you can see, drivers’ trips are filling a lot of the space not covered by the railway (in grey). New areas are now accessible to you in less than 30 min, places such as Evry-Courcouronnes, Créteil, or the east of Paris.

Trips made by drivers currently available during the week, passing less than 2.5 km from Massy-Palaiseau station and ending less than 20 km from it (in blue), regional transport (in grey) — using BlaBlaCar Daily data and

This new map is almost as big as the car’s one, for a fraction of the environmental and economic cost of owning a vehicle. When you’re able to share the trips of drivers passing nearby, your daily territory becomes the fusion of the drivers’ trips.

Of course, you have to find someone who travels at the same time as you. But the probability that a person is driving near your home and close to your destination is rather high: today more than 70% of French workers use their car to go to work, all going their own way, covering the entire territory and potentially going where you need to go.

And this is pretty much everywhere. As shown on the map below, France is filled with driving commuters. Just like you, they probably want to travel maximum 30 minutes away from their place, and just like you, they probably want to travel during morning or evening hours.

Share of the commutes done by car per agglomeration of communes (EPCI) in France
Share of the commutes done by car per agglomeration of communes (EPCI) in France — source

Those are all trips and costs that can be shared, representing a huge opportunity to improve the daily travels of French citizens.

To unlock this potential, drivers and passengers need to connect one way or the other. This is where apps can be very helpful. By building a network covering the entire territory, they are able to find new solutions for most travellers, just like your Massy-Boulogne trip.

Among all those workers driving to work, almost half a million already decided to share their car on BlaBlaCar Daily, covering a big part of France, as mapped below.

Top 1000 drivers route available on BlaBlaCar Daily per French Commune — using BlaBlaCar Daily data and

In total, more than 2 millions users went looking for a carpool on the app. More than 80% of users joining us today are able to find a carpooler they can share their trips with. For passengers, this means moving around more freely while for drivers, it means sharing the cost of traveling and helping someone out.

Carpool is all around you

After months of confinement and movement limitation, you are finally rediscovering the extent of the daily territory. Thanks to carpooling, this territory can be bigger and easier to navigate than you ever imagined.

You might find some new places that were not easily accessible before.

You might reduce your cost and time of travelling.

You might be able to say yes more quickly when invited for dinner.

Thanks to Emilie Baliozian, Adrien Tahon, Clovis Bernier, Jonathan Colak et Lucie Hubert for their careful reading and helpful feedbacks for this article. Thank you Alizée Landeau for the illustration and the BlaBlaCar Daily team for building this vision!



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