徒歩を含むように修正されたtransit network dataset；徒歩の結果が誤っています

psimon

こんにちは！

GTFSネットワークデータセットを作成し、公共交通機関の分析にうまく活用できています。私が知りたかったのは、15分以内の徒歩圏内にあるバス停の数と、場所間の徒歩による移動時間です。

既存のTransit Network datasetを徒歩を移動モードとして含めるように修正しましたが、なぜか誤った結果が出てしまいます。原因が見つからず、アドバイスをいただけるとありがたいです。

興味のある方は、このリンクでデータセットを公開しています：https://arcg.is/1rv4nf

どうぞよろしくお願いいたします。

パトリック

 

Melinda Morang

Hello Patrick.

I looked at your network, and I think I know what the problem is. The WalkTime cost attribute included in the network by default (created from the provided template) is not really meant to be used to model walking only. I realize this is a bit misleading. Essentially it is there to help create a reasonable walk time estimate for use in the transit calculations and so you can accumulate the total walking time used in your transit journeys. For this reason, it calculates the walk time along transit lines (LineVariantElements) and StopConnectors as 0. If you use the WalkTime cost attribute directly, it sees the transit lines as free to use, so your routes will be all weird.

If you want to use this network to model walking, you can do one of two things.

1) Cheat. Use your transit travel mode, but just don't set a time of day. The transit lines will never have any service and will be effectively restricted, and so all calculations will default back to walking.

2) Continue along the route you're currently on, but fix your walking travel mode. The easiest thing is to create a restriction attribute that makes LineVariantElements and StopConnectors restricted all the time and make sure this restriction is turned on for your Walking travel mode.