1. Spatial Network Analysis of Public Transport Accessibility
Accessibility defined as: “whether or not people can get to services and activities at a reasonable cost, in reasonable time and with reasonable ease”
City of Edinburgh Council (2007:82)
Angela Hull and Saleem Karou

2. Components of accessibility in model
Source: Geurs and Wee, 2004

3. Accessibility measures/ indicators
Time access to city centre. representing the actual morning peak hour travel time between a zone and the Central Business Distract (CBD).
A contour measure. describing the total number of economic activities or destinations within a maximum travel time determined based on the trip purpose.

4. 3. A potential accessibility measure
3. A potential accessibility measure. A gravity-based measure using the travel time between data zones, weighted by the quantity of activity opportunities per zone.

5. Activity Opportunity Types used
Attributes of activity opportunities used in the accessibility measurement
Accessibility Indicators
Time of access to city centre
Contour measure
Potential measure
15 minutes
30 minutes
Central Business District (CBD)
N/A √ -
Employment opportunities
The total number of jobs in key sectors including agriculture, financial services, retail, tourism, manufacturing, construction , health, education, defence, social security, electronics, transport and other sectors
Retail
opportunities
The total gross floor area of food shops, supermarkets and other retail services
Education opportunities
Number of pupils in secondary schools and number of students in colleges and universities
Health
Number of outpatients, day patients, and inpatients GP and hospitals
Leisure & recreation opportunities
Number of libraries, cinemas, sport facilities and parks

6. Edinburgh GIS model 549 Data Zones with population 500 – 1000 each
data on land use attributes of each zone including population, employment, retail, health, education, and recreation stored in its own centroid
For larger zones, centroids calculated on basis of population location
Nodes represent the bus and tram stops and ESSR stations on the network
Links are the multi – modal public transit network measured by length and actual morning peak travel times

7. 2010 Baseline (i) Access to the CBD: Parity in journey time between private motorised and public transport; (ii) Bus services

8. Research questions
What is the change in spatial accessibility by public transport within the case study area resulting from the planned enhancements to the local transport network?
What is the contribution of that change to increasing or reducing inequality (measured by accessibility to urban facilities) across case study area?
Where are the gaps in the distribution of the main urban facilities (health, retail, and education facilities) in Edinburgh in terms of the access to their locations by public transport?

9. Ex ante evaluation of strategic transport options