Basemap :: Forum

11/23/2010 12:39:27 PM iang Posts: 10	Hello everyone, I'm trying to create a core bus network based on the number of busses per hour that are on a route. It would appear that when setting minimum service frequency per hour this filter will only select a single service that provides the specified frequency e.g. a service running 4+ busses per hour would be selected if 4 was selected. The problem I have is we have several routes where a mutiple of services provide the required frequency but are not selected because each individual frequency is less than 4. to overcome this I suspended all services that do not provide a combined 4+ frequency on any given route and left the minimum service frequency set to 0. However the results show accessibility identical to when the services are not suspended suggesting the programme for calculating local accessibility ignores any suspension of services. Any ideas anyone? Ian
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11/23/2010 3:12:46 PM admin Administrator Posts: 146	Hi Ian, When the minimum service frequency is set to 0 it ignores all the service information and just looks at the location of the stop, this results in the final output just showing distance from a PT stop. As for a work around - i'm unsure of what to suggest, most of the services should have at least a frequency of 1 an hour so you could put this in. As to get to your minimum of four then there would need to be at least one service an hour for one of the routes? Regards, Dan
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12/15/2010 9:31:39 AM keithdrew76 Posts: 44	Hi Ian I think your, well my, solution may well lie outside Accession, and in a GIS program. To do this you need to get the timetable info into a GIS program and then draw start and end points (for your route). Then capture the services that are in both start and end points. Then create a subset of the main timetable file for those selected services... then run a frequency analysis of the stops in your subset. Select where freq >3 in your selected hour... Keith
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12/17/2010 9:52:04 AM iang Posts: 10	Thanks for this. I have worked round the problem by creating the core network in GIS then drawing a 286m buffer around this (we discussed this on Wednesday). Origins can then be seen to be in or out of the buffer zone. At this stage I am only interested if the origin can access the core network hypothetically, i.e. a bus stop could be added if not already there. If need this I will have a go with your suggestion Keith. Ian
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4/14/2011 9:56:10 AM Jonno1 Posts: 14	I got round this problem by asking the IT department to write a program in visual Basic to run in Microsoft Access to transform the ATCO-CIF file when imported into Access into a relational database with a number of fields. The main building block for subsequent queries was a 'group by' count query based on the total number of calls per stop reference made by all scheduled services, where the stop reference is taken from the QO or QI record, and the 'call' is the scheduled time to arrive at the stop listed further along that record type (used as a 'count'). Other fields identify day of week, and criteria can be used to assess time periods. I used this program to develop a public transport accessibility measure for East Midlands Councils (EMC, previously EMRA) for their annual monitoring report. Also see a paper I've written for the Journal of Maps in 2008/2009 on an assessment of rural bus subsidies/funding.
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