Since the 1971 "Bike Bill" was passed, and the terms "shoulder
bikeways" or "bike lanes" were commonly used, the Oregon Highway Department
advocated building paved shoulders when reconstructing roads. There was also an aggressive
program in the 60's and 70's to add paved shoulders to existing roads. These were often
referred to as "safety shoulders." There are good reasons for this term.
The following are some of the reasons why standard width shoulders are advantageous.
Most are paraphrases of what AASHTO has to say about shoulders. Paved shoulders have
benefits in three important areas: safety, capacity and maintenance. Most of these
advantages apply to both shoulders on rural highways and to marked, on-street bike lanes
on urban roadways.
(A) Safety--highways with paved shoulders have reduced accident rates, as paved
1. Provide space to make evasive maneuvers;
2. Accommodate driver error;
3. Add a recovery area to regain control of a vehicle;
4. Provide space for disabled vehicles;
5. Provide increased sight distance for through vehicles and for vehicles entering the
roadway (in cut sections or brushy areas in rural areas, and in urban areas with many
6. Provide lateral clearance to roadside objects such as guardrail, signs and poles;
7. Contribute to driving ease and reduced driver strain;
8. Reduce passing conflicts between motor vehicles and bicyclists and pedestrians;
9. Make the crossing pedestrian more visible to motorists; and
10. Provide for storm water discharge farther from the travel lanes, reducing
hydroplaning. This also reduces splash and spray to following vehicles and nearby
pedestrians and bicyclists.
(B) Capacity--highways with paved shoulders can carry more traffic, as paved
11. Provide more intersection and safe stopping sight distance;
12. Allow for easier exiting from travel lanes to side streets and roads (also a safety
13. Provide greater effective turning radius for trucks;
14. Provide space for off-tracking of truck's rear wheels in curved sections;
15. Provide space for disabled vehicles, mail delivery and bus stops;
16. Provide space for bicyclists to ride at their own pace;
17. Provide space between motor vehicles and pedestrians, increasing pedestrians level
(C) Maintenance--highways with paved shoulders are easier to maintain, as paved
18. Provide structural support to the pavement;
19. Discharge water further from the travel lanes, reducing the undermining of the base
20. Provide space for maintenance operations and snow storage;
21. Provide space for portable maintenance signs;
22. Facilitate painting of fog lines.