Hey everybody, I am looking to see how I limit the amount of walking to let's say 5 minutes or 800 meters when creating service area or Time Lapse and then the rest is transit travel. Thoughts?
Unfortunately, although this feature is frequently requested, this is not really possible with the transit evaluator and Add GTFS to a Network Dataset toolbox, as mentioned in the "Limitations and weaknesses" section of the User's Guide. This problem is because of the way the Network Analyst solvers work under the hood. They do not have the ability to separately track and limit different states (walking vs. transit).
For the Service Area Lines output only, you can kind of hack it to sort of do what you're asking. You should continue to use your transit travel time cost attribute as the impedance attribute. But, additionally, you should set the accumulate attributes to accumulate a walk time attribute. For streets, the walk time attribute should use the same evaluator calculation as the transit travel time attribute. However, for transit lines and the stop-street connectors, you should set the evaluator to a constant of 0. You could also choose to make this attribute calculate walking distance instead of time. When you accumulate this attribute, it will add time or distance whenever the streets are traversed (where the traveler is walking), but it will not add any impedance for travel along the transit lines and connectors. Then, you can eliminate all output Lines where the accumulated walk time or distance exceeds your threshold.
Yes, I'd recommend you read this thread as a customer had a similar question. With the Network Analyst extension, you'd be able to generate a service area for walking.
Hi Robert. Thanks for the reply, I am not looking to make a walkability service area. I am looking to make a transit service area to a location and limit the amount of time walking to 5 minutes or so. Example: a 20 minute travel time with only 5 minutes of walking to and from stops and the rest, 15 minutes, is wait time or transit travel.
Robert, the customer is specifically asking about solving network analysis using the Add GTFS to a Network Dataset toolbox. A Service Area generated with a transit-enabled network dataset created with that toolbox will show the area reachable by transit and walking within a time limit. The customer wants to know if there's a way to limit the walking time separately from the overall travel time. For example, I'm willing to travel for an hour, but I won't walk more than 10 minutes. The other 50 minutes can be spent sitting on a bus. The answer to the question is no, the Add GTFS to a Network Dataset stuff (and the Network Analyst solvers) doesn't support this, as explained in my other comment.
Ah okay - thx for the clarification Melinda!
Hi Melinda: Thanks for taking the time to reply. I have read most of your web content, I must have missed this in the User's Guide. I will give your hack a try and see what the results are. I hope to see your team in Palm Springs in March, would love to see what's new in Network Analyst.
Okay, good luck. I personally will only be at DevSummit on Friday morning, but various members of my team will be around all week if you have general Network Analyst questions.
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