Bicycle Level of Service (BLOS) is a nationally-used measure of on-road bicyclist comfort level as a function of a roadway's geometry and traffic conditions. Developed by Sprinkle Consulting, BLOS is in the Highway Capacity Manual. Ride Illinois developed this calculator for the published BLOS formula for roadway segments.
To calculate BLOS of a particular roadway section, fill out the following for the typical cross-section. Default values will be used for any fields left empty. Results will pop up in a new window. Our own rule of thumb: BLOS grades A/B/C are "comfortable enough" for more experienced cyclists, as are A/B for a broader range of adults. If necessary, each group is usually willing to ride a road that is a half or full grade worse, but they will be uncomfortable doing so.
Some details on the BLOS input fields and their ranges are below. (Be cautious when using inputs outside the model's ranges.)
The following provides further information on the BLOS data inputs. See Sprinkle's paper for more.
Roadway parameters will often change, and averaging could be done depending on the situation. In general, try to select a typical cross-section.
| Through lanes per direction: | Do not include medians, turn lanes, or continuous-left-turn lanes. |
| Width of outside travel lane, to outside stripe (in feet): | Width of right-most travel lane, excluding striped paved shoulders, bike lanes, and marked parking stalls. |
| Paved shoulder, bike lane, OR marked parking area, outside lane stripe to pavement edge (in feet): | Besides a paved shoulder or a bike lane, this width may also be marked (striped or hashed) parking stalls. For diagonal parking, use the perpendicular distance from the end of the parking stripes to the pavement edge. This calculator does not work when there are BOTH bike lanes and parking stalls - please see the reference for this case. |
| Bi-directional Traffic Volume (in ADT): | Daily average. Assumed Directional factor (0.565) and Peak Hour Factor (0.091) values are used in a conversion to peak 15-minute volume. |
| Percentage of heavy vehicles: | As defined in the Highway Capacity Manual. |
| FHWA's pavement condition rating: | For a longer term view normalizing the point at which a road is in its repavement cycle, use 4 as an average. |
| Percentage of road segment with occupied on-street parking: | Exclude driveways. Either one side or an average of both sides may be considered at a time. |
Be aware of model use outside these ranges, particularly for paved shoulders much over 6 feet and more than a few percent heavy vehicles. Try halving incremental shoulder width over 4 feet (e.g., use 7 for a 10-foot shoulder), and compressing heavy vehicle percentage above 2% so that, for example, 5% is high and 7% is extremely high. Another suggestion: if occupied parking is greater than 10%, estimate high or use a peak value.
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Last update 10-20-2016, Ed Barsotti, Ride Illinois