Road Chainages + Styled Checkboxes

Roads (Visibility + Chainage Ranges)

Use 0-500,1000-2000 format. Highlights: Red=Budgeted, Green=DLP, Pink=AMC
Always export GeoJSON to save your work!
User Standard Operating Procedure: GIS Road Chainage & Asset Management Application

Standard Operating Procedure & User Guide

System: Web-GIS Road Chainage Tracking & Maintenance Monitoring Tool

Target Audience: Project Managers, Site Engineers, Surveyors, and Contract Administrators

1. Executive Overview & Application Purpose

This web-based GIS application is engineered to streamline infrastructure inspection, asset tracking, and maintenance operations along linear highway assets. By converting standard spatial files into structured linear referencing systems, the tool allows site engineers to visualize alignment chainages, pinpoint ongoing contract liabilities, and verify physical works directly in the field using GPS positioning.

2. Key Civil Engineering Features

  • Linear Chainage Generation: Automatically computes and labels linear stations (e.g., 0+000, 2+000) perpendicular to the road centerline geometry using Turf.js spatial analysis.
  • Dynamic Maintenance Zone Overlay: Overlays designated road stretches belonging to specific contractual obligations directly onto the polyline alignment.
  • On-Site GPS Tracking: Provides field engineers with live geolocation capabilities to match physical ground locations against project chainages.
  • Multi-Format Data Portability: Native import capabilities for survey Keyhole Markup Language (.kml) files and full state export via GeoJSON formats.
  • Local Data Persistence: Stores alignment and status data within the local browser storage with dynamic memory warning thresholds.

3. Field Operations & Feature Maintenance Matrix

Contractual works are visually color-coded along the alignment to enable instant identification of road condition responsibilities during site audits:

Category Map Indicator Engineering Description & Use Case
Budgeted Works Red Line Overlay Capital works, capital improvement projects, or planned reconstruction segments allocated under approved financial budgets.
Defect Liability Period (DLP) Green Line Overlay Recently completed segments under the contractor's warranty period. Any structural failure within these bounds must be rectified by the contractor at zero client cost.
Annual Maintenance Contract (AMC) Pink/Magenta Overlay Segments under routine operation and maintenance contracts (e.g., pothole patching, line marking, shoulder clearing).

4. Step-by-Step Operating Instructions

Step 1: Importing Alignment Files

  1. Click Choose Files adjacent to the controller panel.
  2. Select one or multiple KML files exported from Google Earth, Civil 3D, or survey devices.
  3. The system automatically indexes each alignment as R1, R2, etc., and calculates initial chainages starting at 0+000.

Step 2: Configuring Chainage Parameters

  • Fixed Interval: Uncheck Auto by Zoom and input a specific meter value (e.g., 500 for 500m intervals) into the Chainage Interval (m) field, then click Apply.
  • Adaptive Zoom (Recommended): Leave Auto by Zoom checked. The system dynamically scales marker density depending on your map zoom level to prevent visual clutter:
    • Zoom Level < 8: 100 km intervals
    • Zoom Level 12–13: 2 km intervals
    • Zoom Level ≥ 16: 200 m intervals

Step 3: Assigning Maintenance Ranges

  1. Locate the target road row under the Roads section.
  2. If the survey start point is not zero, update the Start input box with the structural starting chainage in meters (e.g., entering 5000 shifts the starting station to 5+000).
  3. Input maintenance chainage intervals using the required format: Start-End. Separate multiple segments with commas.
    • Example: To mark Budgeted works from chainage 0m to 500m and 1000m to 2000m, enter 0-500,1000-2000 in the Budgeted field.

Step 4: Executing Field Inspections

  1. Click Show My Location when performing physical field audits.
  2. The map will center on your device's live GPS coordinates, displaying an accuracy radius circle.
  3. Compare your real-time blue marker against the road chainage labels to verify asset positions, cut/fill boundaries, or defect locations without manual chaining.

5. Data Backup & Storage Management

This application utilizes browser local storage (localStorage) to maintain state without requiring an external database server.

CRITICAL DATA SAFETY NOTICE: Local storage capacity is capped by web browsers at approximately 5 MB.
  • If storage usage exceeds 75%, a warning message will appear in red text.
  • If storage reaches capacity during an import, an EMERGENCY_EXPORT.geojson file will automatically download to prevent data loss.
  • Always click Download GeoJSON at the end of every working session to export your master project file to local disks or corporate cloud drives.
  • To clear data or start a new project site, click Clear All Data only after verifying your saved .geojson export.