Animated flow of Rotterdam citizens
Research Assistant Anders Sorgenfri Jensen
Associate Professor Henrik Harder
Diverse Urban Spaces
Department of Architecture, Design and Media Technology
Aalborg University
Denmark

Diverse Urban Spaces
• Research group at Department of Architecture, Design and Media
Technology, Aalborg University, Denmark
• Small group of specialists (chartered surveyors, architects, sociologists, geographers)
• Mobility
• Lots of project similar to the Rotterdam High Rise data

Various projects, same basic work routine, varying details
• Equip a specific population group with hand-held GPS-receivers for a predefined time period
• Gather data
• Execute an array of different data processing procedures upon the gathered data depending on the setup and objectives of the survey

Projects
Project Population group
Helpark (2007) Park visitors
Diverse Urban
Spaces (2008)
High school students
Bikeability (2010) Bicyclists
ACTUM (2011) Families
Helpark 2 (2011) Park visitors
Survey period Respondent count
4462 Varying (max 1 day)
1 week 250
1 week
1 week
Varying (max 1 day)
210
188
1065 www.detmangfoldigebyrum.dk

Animated flow - history
• Originated in one of the earliest projects (2006)
• Student assitants were employed to manually change map content and export image files
• Images could be strung together to an animation using video editing software
• Approximately 1000 image files were required for a single animation

Animated flow - history

Animated flow - history
• Procedure worked, but it was:
• Expensive
• Bulky and cumbersome
• Any desire of changes with regard to content or layout would require a complete reiteration of the manual labour
• Consequently, flow animations were abandoned in later projects

Animated flow - history
• Years later, the approach was picked up again during the Helpark 2 project
• Something similar to CASA’s London Bike flow

Animated flow - history
• Greater degree of knowledge through years of experience
• Previously manual routines were automated through Python scripts
• These scripts were used for the Rotterdam-animation

Method
• Python + arcpy
• Mapping module allows for changing map documents from within a script
• Through the definition query and the GPS data’s timestamp attribute, various time intervals can be shown
A time interval as defined by the definition query
A different time interval as defined by a different definition query

Method – time definitions and relations
• Overall time frame – the time portrayed by the animation
• Time interval – the time portrayed by a single image
• Time shift frequency – the difference in time between two subsequent images

Method
• Put inside a loop
• Add export routines
• Execute script

Method
• Additional processes are added
• Points are converted to lines
• Accumulated date is occasionally aggregated into a grid which depicts time expenditure from the start of the animation up untill the current frame

Result
• The result is very complex
• Dates are aggregated
• The movement of a single respondent is represented several times across different dates
• The scale of the map is too big to depict the behaviour in the central areas of the city
• Extracting information from the animation requires knowledge of the city and points of interest as well as the respondents’ daily life

Thank you for your attention
• Questions?