RIRO expressway
From Biocrawler, the free encyclopedia.
A RIRO expressway (right-in, right-out) is a kind of freeway that does not meet the expectations of a standard freeway due to elements such as sharp ramps and only one lane in each direction.
| Contents |
[edit]
Elements
The following elements may be part of a low-budget freeway:
- Sharp off- and on-ramps, sometimes like at a standard intersection (also called right-in right-out (RIRO) ramps).
- Direct driveway access from adjoining properties.
- Lack of a median, or only one lane in each direction (a super 2).
- A drawbridge or railroad grade crossing.
[edit]
Here are elements that can be part of it that are also part of normal freeways:
- Design speed of 65 mph (100 km/h) or more
- 2+ lanes on each side
- Interchanges
- grade-separated crossings
- Any Interstate-standard elements
If a road includes at-grade intersections with cross traffic, it is typically considered an expressway.
[edit]
Examples
- Despite the prohibition in Interstate standards, a few Interstate Highways in the U.S. West have at-grade intersections. Some only allow access in one direction, but others include median breaks.
- Highway 115 and parts of Highway 11 in Ontario have sharp ramps and property access in various sections. There are no breaks in the median, and to turn around one must exit the highway at an interchange or special turn-around ramp and re-enter the highway in the opposite direction. However, the sections on Highway 11 are expected to be upgraded to a full freeway in the future.
- U.S. Highway 90A (South Main) in Houston, Texas has property access on one side of the median, but all crossings are grade separated, with access to the roadway provided only by interchanges (i.e. Jersey freeway).
- U.S. Highway 50 between Washington, D.C. and Queenstown, Maryland is a freeway, however there are several cases of sharp exits between Annapolis, Maryland and the end of the freeway in Queenstown.
[edit]
Cartographic circumstances
- Freeways that have oddities like the ones aforementioned are often marked as divided highways on road maps.
[edit]
