Constraints fall into several categories:

**Physical Constraints** - Vertical clearances (bridges, overpasses, utilities) - Horizontal clearances (lane width, barriers, structures) - Road geometry (curves, grades, intersections) - Pavement conditions and weight limits

**Regulatory Constraints** - Permit requirements by jurisdiction - Weight limits by road class - Time-of-day and day-of-week restrictions - Seasonal restrictions (frost laws, spring thaw) - Escort and pilot car requirements

**Operational Constraints** - Staging areas and turnaround points - Fuel and rest facilities - Emergency response access - Traffic management requirements

A constraint is not inherently a "no-go" — it is a factor that must be understood, documented, and addressed. The goal is not to avoid constraints but to manage them.