# How to create a network buffer around a polyline feature?

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08-23-2016 12:29 PM
New Contributor III

I'm trying to create a travel distance buffer around a freeway segment using time or distance on a network?  I'm using ArcMap 10.3.1. Is this even possible?  In Network Analyst the only thing I can seem to do is add point features to create service areas.

3 Replies
MVP Alum

That's what NA is about, not so. As long as you have a network to analyse of course (often the most difficult bit).

That's an allocation problem.

What is Network analyst

MVP Alum

Can you draw a picture of what you are trying to achieve?  It may be possible to do this with Network Analysis, but I'm not entirely clear on what you are trying to accomplish.

For example, is the freeway segment being treated as a linear "starting point" and you want to find the maximum distance one could travel away from any part of that segment in a set amount of time?  If so, one approach would be derive points from all intersections of the "starting point segment" and roads contacting it, then run a Service Area for each point, then combine them.  This could be set up in Modelbuilder using an Iterator or programmed in Python to automatically run all the possibilities and then combine them into the result.

Chris Donohue, GISP

New Contributor

As far as I know, there is no function in ArcGIS Pro or Desktop that can create a network distance buffer centered at a line. Service area function provided in Network Analyst can only create network distance buffers centered at points. The way to create network buffers around a line is to transform the task to create network buffers centered at points and then dissolve. For example, you have a freeway segment, and there are two nodes (original node and destination node) which belong to the freeway. We want to find more nodes along the freeway. The way to find nodes along the freeway is to find the intersections of the freeway segment with other roads. Once you have the nodes along the segment, origin node, and destination node, you create network buffers centered at these nodes, and then dissolve the network buffers.

Like the attached image shows: The red line is the freeway segment, the blue lines are other road segments, the green points are the intersection nodes, and the yellow nodes are origin and destination nodes . We can create network buffers centered at each points and then dissolve the network buffers.