Break Long Polylines into Equal Segments in AutoCAD — The Right Way

Have you ever tried dividing a long polyline in AutoCAD, only to realize that AutoCAD marks points but doesn't actually split the line? This is a common frustration, especially when working with road alignments, utilities, pipelines, or survey drawings.



📐 Understanding DIVIDE and MEASURE

Let's say you have a 5,000-meter polyline and want it split into ten equal segments. Using the DIVIDE command, AutoCAD places nine equally spaced points along the polyline. While this visually marks the locations, the polyline remains a single continuous object. DIVIDE does not break geometry — it only indicates positions.

The MEASURE command works similarly but is interval-based. For example, entering 500 places points every 500 meters along the polyline. You can even locate an exact distance, such as 2,600 meters from the start, which is extremely helpful for curved or complex polylines.


👁️ Making Points Visible

If Divide or Measure points appear too small or invisible, AutoCAD provides full control over their display. Using PDMODE and PDSIZE, you can choose clear, visible point styles so all division markers are easy to identify.


❌ Why Native Commands Fall Short

Despite their usefulness, DIVIDE and MEASURE only create points. They do not physically break the polyline. If your workflow requires actual segments — separate polylines with measurable lengths — AutoCAD has no direct built-in command to do this efficiently.


🚀 FREE AutoLISP Solution - SegPl Command

This is where automation comes in. We've developed a powerful FREE AutoLISP routine that actually breaks polylines into real segments.

📥 FREE Download: Watch & Download File From Description

📋 Load: Use APPLOAD command
▶️ Run: Type SegPl command
⚡ Usage: Select polyline → Enter interval (ex: 500)

The routine automatically:

  • Breaks the polyline into individual segments

  • Labels each segment with its distance

  • Places all resulting geometry on a dedicated layer named BrokenLine

🏗️ Perfect for Engineering Workflows

  • Surveying

  • Road design

  • Utility layouts

  • Irrigation planning

  • Any segment-based analysis

This solution saves time, eliminates manual errors, and delivers results AutoCAD simply doesn't provide out of the box. Once you use it, you'll never look at DIVIDE the same way again.


💼 Need Custom AutoLISP Solutions?

If you need a tailored AutoLISP solution for your specific CAD workflow, feel free to reach out:
📧 cadsuperuser@gmail.com