SafeWalk is an app that calculates the safest walking routes in NYC between two points by considering major crimes data and one's personal fear of crime. It uses k-nearest neighbors and Dijkstra's algorithm on OSM road and crimes datasets to associate crimes with roads and find shortest paths minimizing crime costs. Route comparisons demonstrate how routes can vary significantly based on time of day and individual fear levels. The app aims to balance route length with safety based on customizable personal parameters.
2. Problem Statement
● Is the shortest route always the “safest” route?
● Given major crimes data, compute optimal
walking route between two points in ANY of the
NYC boroughs.
OSM Data
for NYC
(~650,000 roads)
Major Crimes
Dataset
2005-2016
(~1,000,000)
3. Algorithms
● K-nearest neighours classification to associate
each crime with a road. Build directed graph
● Dijkstra Algorithm: between two nodes (red and
green) find the shortest path minimizing the
sum of weigths Robbery at
(40.1345, -76.314341)
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w3 w6
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4. KISS Model for Crime Cost
elongated
road length
original road
length
Personal fear of crime Crime Costs depending
on hour and type of
crime
5. App Landing Page
● Personal Fear of Crime: Rational, Almost rational, Borderline irrational, Irrational,
Paranoid
6. Brooklyn Routing at 0100
● Crime Avoidance Level : Neutral, Personal Fear of Crime: Rational
10. Insights
● NYC is pretty safe at any time of time of day
(Nice! but not for me).
● One’s perceived ‘fear’ of crime can lead to
significant route modificationss
● There exists a trade-off between route length
and safety
12. Demos!
● Brooklyn neutral Show time of day
● Port Harris Neutral vs Paranoid Show personal
fear of crime parameter
●
13. About Me
● What I do besides solving (numerically) partial
differential equations.
●
14. KDE
● Cool figure of crime density goes here
●
● : number of crimes (type i) on road/total
number of crimes (type i) in precinct
● :
● : total number of crimes on road/total number
of crimes in precinct