Proper clearance surveying requires:

**Equipment** - Calibrated measuring devices (laser rangefinders, height poles) - GPS with sufficient accuracy for location documentation - Camera with timestamp and location embedding

**Methodology** 1. Approach each structure systematically 2. Measure at the lowest point across the travel lane 3. Document both the clearance AND the measurement point 4. Photograph the structure with measurement visible 5. Note any factors that could affect clearance (road crown, seasonal variation)

**Documentation Standards** - Record GPS coordinates for each measurement - Note date, time, and weather conditions - Document measurement method used - Identify who performed the survey - Include reference photos from multiple angles

**Common Errors** - Measuring at road edge instead of travel lane - Ignoring road crown or pavement overlay potential - Not accounting for seasonal vegetation - Failing to identify the limiting point across the span