Naming Standards
Numbered US Highways shall be named as: US-###
Numbered State Highways shall be named as: SR-###
Major Interstates
Interstate 89 - From Concord to Lebanon (60.80 mi)
Interstate 93 - (Portions Toll) From Salem to Littleton (131.39 mi)
Interstate 95 - (Portions Toll) From Seabrook to Portsmouth (16.11mi)
Interstate 293 - From Manchester to Hooksett (11.18 mi)
Interstate 393 - From Concord to Pembroke (4.50 mi)
Locking roads
In New Hampshire we have a set minimum standard for locking roads based on segment type. Any road of a certain segment type must be locked at least to the rank (level) in the chart below. Roads may be locked higher for protection and special situations (areas with construction, tricky design, frequent mistakes, imaging inaccuracies, and the like), but should not be locked lower.
A great time to implement these locks is while bringing the road types of an area into compliance with the current US road type standards (FC and highway systems). Lock the roads based on type after they've been set to current US road type standards.
| Segment Type | Statewide |
|---|---|
| Freeway | 5 |
| Ramp | Highest rank of connected segments |
| Major Highway | 4 |
| Minor Highway | 3 |
| Primary Street | 1 (Auto) |
| Street | 1 (Auto) |
| Private Road | 1 (Auto) |
| • • • • Ferry • • • • | 5 |
| |-|-|-|-|-|-|-|-|-| Railroad |-|-|-|-|-|-|-|-|-| | 2 |
Note: Do Not Mass Edit just to update locks to these standards, these can be adjusted as you find them while editing other aspects of the segments such as FC, speed limits, naming, etc.
Some segments still warrant higher locks and care should be taken when setting segment lock to these standards to look for and protect these special setups with higher locks. Some examples; segments which are part of BDP, U-turn prevention, or using micro-doglegs, or other complex intersection setups.
Functional Classification of Roads
New Hampshire is participating in the new Functional Classification (FC) across the entire state. Some highways may be downgraded, others may be upgraded.
State FC Resources
- NHDOT District Map (pdf) - Regional Planning Commissions (RPC)
- NHDOT State FC Map (pdf)
- NHDOT District FC Maps (See District Map to know which FC map to get) - Scroll down to "Roads By Function" and then click on the appropriate RPC Map.
NHDOT to Waze conversion table
The numbers correspond to the FC type indicated. (e.g. Class 6 road is a Minor Arterial)
| Highway Systems | ||||||||
|---|---|---|---|---|---|---|---|---|
| Interstate | US Hwy (incl. some special routes) | State Hwy (incl. some special routes) | State Hwy BUS, SPUR[a], LOOP | Locally-maintained | ||||
| example>>>>> | I-95 N | US-2 | SR-27 (SR-27A) | SR-400 Loop | Robertson St | |||
| F u n c t i o n a l C l a s s |
Interstate (1,11) | Fw | n/a | n/a | n/a | n/a | ||
| Other Freeways & Expressways (12) | n/a | Fw | Fw | Fw | Fw | |||
| Other Principal Arterials (2,14) | n/a | Major | Major | Major | Major | |||
| Minor Arterial (6,16) | n/a | Major | Minor | Minor | Minor | |||
| Major Collector (7,17) | n/a | Major | Minor | PS | PS | |||
| Minor Collector (8) | n/a | Major | Minor | PS | PS | |||
| Local Roads (9) | n/a | Major | Minor | PS | Street | |||
Match Rural FC labels to its Urban FC counterpart
A US Highway should never be typed lower than Major Highway (MH)