MAtlas: a case study on Milano, Italy

Dataset info GPS traces

17K private cars

one week of ordinary mobility

200K trips (trajectories)

Milan, Italy

Data donated by OCTO Telematics Italia

Overall view of trips performed in a single day (Wednesday, April 4th, 2007)

Difficult to understand anything

Temporal analysis: intensity of traffic (n. of moving vehicles) per hour over the week

The same double-peeked shape for all days, a bit lower in the weekends

Distribution of lengths of the trips

Neat power-law → several short trips, few very long ones

Distribution of trip duration

Another power-law, similar shape

How do length and speed of trips correlate?

Average length grows with avg. speed (right plot)

Yet, only slow trips reach considerable length (left)

Where is traffic concentrated between midnight and 2 a.m.? (red = most intense)

Where is traffic concentrated between 6 a.m. and 8 a.m.?

Where is traffic concentrated between 6 p.m. and 8 p.m.?

Select only trips that start in the city centre (orange) and move to North-West

Behaviours are still rather heterogeneous

Notice the O/D matrix navigation tool on the right

Trajectory clustering divides trips based on the route they cover

Different color = different group

Outliers are removed

Three sample clusters are highlightedOne group (red) goes straight to NW, the others follow

alternative routes

Temporal analysis on each group tells us when they perform the trip

A small group in the morning (commuters working outside the city?) a much larger one in the afternoon (incoming commuters?).

Origin/Destination analysis is flexible

Analyze traffic from/to city areas to/from parking lots

Focus on a specific (high frequency) parking lot, close to Linate airport

Analyze typical itineraries followed to reach such parking lot

T-Patterns → overall view

T-Patterns: highlight one pattern that comes from the centre

T-Patterns: highlight one pattern that comes from North, along the “tangenziale” (ring road)

T-Patterns: highlight one pattern that comes from South, along the “tangenziale” (ring road)

Where is people between 6pm and 8pm of Wednesday, April 4th?

Where is people between 8pm and 10pm of Wednesday, April 4th?

An high density spot appeared

Where is people between 10pm and midnight of Wednesday, April 4th?

The dense spot disappeared. What happened?

Focus on the high-density spot

Centered on the parking lots of the stadium

April 4th, 2007: a football match took place there...

Have a close look at when people arrived to the stadium, and when they left

Through O/D matrix tool, focus on traffic from/to stadium area

Arrivals and departures distributed as expected (concentrated resp. before and after the match)

Small surprising result: some people start leaving around 30 minutes before the match ended...