A Safer Alternative: Cul-de-sacs and Crime

in Durham, NCChris Whittaker

Introduction

The cul-de-sac is a hallmark of suburban sprawl

Advantages: Development of awkward land plots Privacy Less traffic Lower passing vehicle speed

Disadvantages: Disconnected communities Encourage automobile use Produce urban congestion elsewhere Inefficient provision of public goods

Why cul-de-sacs?

Popular perception of lower crime Criminals avoid areas with only one exit Community policing

Little academic research exists

It is difficult to untangle socioeconomic variables from the spatial layout of these communities

However, it remains a useful exercise to conduct natural experiments

Brief Crime History of Durham

Brief Crime History of Durham

Methodology

Identified communities using Google Maps and Zillow

Created 36 cul-de-sac and two-way street pairings

Compared pairings with ~15,000 pieces of criminal activity data

Narrowed to single-family dwellings (note: possible townhomes, though largely removed)

Divided crime into three categories: burglary, larceny and assault

Findings

Yields a 1-to-4.93 cul-de-sac to two-way street crime ratio

Case Study: Pearson Dr. vs. Paladin Ct.

Case Study: Pearson Dr. vs. Paladin Ct.

Pearson Drive (~20 homes): 7 crimes committed 5 Burglary/Breaking and Entering 1 Simple Assault 1 Larceny

Paladin Court (8 homes): 1 crime committed 1 Burglary/Breaking and Entering

Case Study: Bernice St. vs. S Plum St.

Same day

crime

Case Study: Bernice St. vs. S Plum St.

S Plum Street (~39 homes): 5 crimes committed 4 Burglary/Breaking and Entering 1 Aggravated Assault

Bernice Street (~23 homes): 2 crimes committed 2 Burglary/Breaking and Entering

Atypical cul-de-sac design

Case Study: Wyman Pl., Wise Pl., Brownlee Pl. vs. Crowell St.

Case Study: Wyman Pl., Wise Pl., Brownlee Pl. vs. Crowell St.

Crowell Street (~21 homes): 6 crimes committed 2 Theft from a motor vehicle 1 Simple Assault 1 All Other Larceny 1 Burglary/Breaking and Entering 1 Theft from a Building

Wise Place, Wyman Place, and Brownlee Place (~17 homes): 0 crimes committed

1818 Crowell Street

Theft from a motor vehicle (larceny) on 4/5/12

Theft from a building (larceny) on 11/1/12

Discussion

Housing volume and lot size concerns

Selection bias

Spatial permeability

Affluence

Ultimately, correlation does not prove causality

Afterthoughts

Conduct potential future research to better separate spatial and socioeconomic considerations

Add more cul-de-sac communities

Compare findings to similar cities

Expand spatial-criminal research to identify communities with highest level of criminal activity