The Rating System - Bicycle Level of Service
In an effort to provide cyclists with information on the suitability of roads for cycling in the state, the Illinois Department of Transportation (IDOT) calculated a bicycle level of service (BLOS) for thousands of road segments. IDOT maintains a computer database on most roads in the state and used this to generate six scales of bicycle service. These scales were color-coded on these maps, from bright green for most suitable to dark red for least suitable. The following factors are included in the calculation of the BLOS.
As an example, a road with moderate traffic may still rate high for suitability if it has wide outside lanes, wide shoulders, and a good road surface.
All gravel and earth-based roads are shown as gray and the BLOS has not been calculated for them. These roads are generally unsuitable for bicycling. However, roads with an oil-and-chip surface provide a hard surface suitable for riding and have been included. Bicyclists should exercise caution, however, because the suitability of this and all surfaces can vary with the seasons and the general conditions of the particular road.
All roads that have been assigned colors are re-assessed every three years, so it is possible that roadway conditions, and thus ratings, may have changed since the information was gathered.
These green/yellow/red ratings are offered only as general information for adult cyclists of average or better than average experience and who are comfortable sharing the road with vehicular traffic. (Note: This map is not intended as a guide for children.) More experienced cyclists may find the yellow roads very satisfactory, but this comfort level will vary on a person-to-person basis. Inexperienced bicyclists should exercise added caution and ride with more experienced cyclists.
Vertical grades (hills) are numerous in the southernmost and northwestern portions of our state. This information is not included in the rating system at this time. An experienced cyclist knows hills can present significant physical challenges and recognizes that precautions should always be taken when cresting hills that could limit the cyclist's visibility to vehicles coming from behind. Cyclists should always ride on the right edge of the roadway and comply with all bicycle rules of the road. We recommend the use of pole-mounted flags for added visibility.
Roadways are generally designed to keep rush-hour traffic at a tolerable level. Although the ratings for roadways on this map are partially based on average and peak traffic, roads that are more tolerable at off-peak times may be more intolerable for cycling at rush hour. Additionally, roads around resort or recreational areas (which may be marked green on the map) may be subject to periodic or irregular high-volume traffic. Before you plan a bicycle trip, determine which sites along your intended route are having special events. Not all traffic peaks can be anticipated.
We have attempted to include as much useful information as possible without cluttering the map. Not all information can be included. We hope this map is a useful guide as you plan your bicycling excursion. Always wear a helmet and obey the rules of the road. Have a safe and enjoyable trip.