- Delaware uses SR-## for all state routes (e.g. SR-58)
- If the primary name is a street name and the road also has a US or state route (SR), add it to the alt name. If a divided road, also add the cardinal direction to the alt name. e.g. "SR-7 N" on the northbound side and "SR-7 S" on the southbound side. When using alt names, be sure to be consistent and avoid gaps in naming, as this can cause routing issues with detour prevention. If the road switches back and forth between divided and two-way you should add a simple SR-n alt for the length as well to avoid detour prevention.
- Generally, regarding state route numbers, even numbers run east-west and odd numbers run north-south
- Some Delaware routes are continuations from other neighboring state routes. e.g., SR-273, SR-896, SR-299.
Locking standard
In Delaware 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 | 4 |
| Ramp | Highest rank of connected segments |
| Major Highway | 3 |
| Minor Highway | 3 |
| Primary Street | 1 |
| Street | 1 |
| • • • • Ferry • • • • | 5 |
| |-|-|-|-|-|-|-|-|-| Railroad |-|-|-|-|-|-|-|-|-| | 2 |
Elevation
Delaware uses a real elevation method to set road elevations. This method sometimes requires the use of extra segments. This has the benefit of an enhanced look in the Live Map, and, more importantly, makes it easier to close a bridge or tunnel without affecting traffic to nearby homes and businesses.
