Every month in the Webinar series a member of our team or invited expert, presents either recent research results or a city case study. The presentations are done online allowing people anywhere to participate and ask questions in real-time. The series address issues relevant to researchers and practitioners and is open to everyone using our news website. About 800 subscribers get the announcement directly, you can also sign up for free here.
3. Locational accessibility indicators
• Transportation is means to an end
• Cumulative opportunity and gravity metrics
• Accessibility indicators can foster more
sustainable outcomes but are not yet been
widely implemented in practice
Hansen (1959)
Black and Conroy (1977)
Handy and Niemeier (1997)
Papa et al. (2016)
Boisjoly and El-Geneidy (2017)
4. Locational accessibility indicators
• Policy relevance
• Online communication
• ao.umn.edu
• tfl.gov.uk/webcat
Hansen (1959)
Black and Conroy (1977)
Handy and Niemeier (1997)
Papa et al. (2016)
Boisjoly and El-Geneidy (2017)
6. Probabilistic approaches to accessibility
measurement
• Accessibility by transit is subject to
variation and uncertainty
• Variation due to departure time
• Uncertainty due to
“underspecified” scenarios
• Conveyal Analysis
• 200m grid cells
• Complete-journey travel times
for every possible departure
minute over a specified window
• Monte Carlo simulation when
explicit timetables are not
specified
Conway, Byrd, and van der Linden (2017)
Conway, Byrd, and van Eggermond (under review)
7. Open,cloud-basedsoftwarefor rapidscenario
modificationandevaluation
conveyal/analysis-backend
Data management on cloud-
computing clusters
conveyal/analysis-ui
Browser-based interface for
scenario editing and evaluation
Accessibility and travel
time results
Transit
modifications
Transit schedules
(GTFS)
Road network
(OpenStreetMap)
Land-use data
(e.g. LEHD, shapefiles)
conveyal/r5
Multimodal routing engine
Selected origins
and routing options
Travel times from origin to all
potential destinations
Baseline
data
8. Open,cloud-basedsoftwarefor rapidscenario
modificationandevaluation
conveyal/analysis-backend
Data management on cloud-
computing clusters
conveyal/analysis-ui
Browser-based interface for
scenario editing and evaluation
Accessibility and travel
time results
Transit
modifications
Transit schedules
(GTFS)
Road network
(OpenStreetMap)
Land-use data
(e.g. LEHD, shapefiles)
conveyal/r5
Multimodal routing engine
Selected origins
and routing options
Travel times from origin to all
potential destinations
Baseline
data
conveyal/taui
MITtransportanalyst/coaxs-react
Other interfaces for wider
communication
23. The most accessible job in Greater London is within a 45-minute
commute (walking + public transport) of 1,813,144 workers
23
24. The median job in Greater London is within a 45-minute commute
(walking + public transport) of 712,753 workers
24
25. Unsurprisingly, industries with firms that tend to locate centrally have
higher accessibility to the overall workforce.
25
0
5
10
15
20
PercentofJobsinIndustry
Thousand workers within 45-minute commute
Distribution of Accessibility to Workforce
Finance
Manufacturing
26. Such firms may also benefit from an additional connectivity advantage
based on their workers’ residential location patterns.
26
Percent of Workforce reachable
(within 45 minutes via walking
and transit) by industry
AllWorkers
Manufacturing
Workers
InformationWorkers
Finance
Workers
HealthcareWorkers
All Employers 18%
Manufacturing Employers 10% 10%
Information Employers 25% 31%
Finance Employers 37% 46%
Healthcare Employers 14% 13%
Adv -1% 25% 26% -6%
• Workplaces with high wage/high
qualification jobs tend to be
centrally located, and related
employees tend to reside in
highly accessible locations.
• Thick labor markets have
agglomeration benefits related
to, but potentially distinct from,
“effective density” benefits
currently included in DfT
Transport Appraisal Guidance
28. Accessibility-based reliability indicators
• “Ring of unreliability”
(Cui and Levinson 2016)
• Percent difference between real-
time and actual access scores
(Wessel, Allen, and Farber 2017)
