Provided below is a brief example of how the BCI model can be applied in the assessment of design alternatives for a roadway that is being planned for reconstruction. A minor arterial that connects a suburban area to the major arterial used for commuting into and out of downtown is being widened from two lanes to four because of a projected increase in volumes. The development along the roadside is a combination of retail businesses and light commercial industries. The current average annual daily traffic (AADT) on the roadway is 10,000 vehicles per day (vpd) with 2 percent truck traffic, and the projected AADT in five years is 16,000 vpd with the same percentage of trucks. Motor vehicle speeds on the facility currently have an 85th percentile of 50 km/h; with the additional lanes, this value is expected to increase slightly to 55 km/h. The original proposed highway department design (see figure 21) within the 20.0-m right-of-way included 3.6-m wide lanes, a 1.0-m wide planting strip on each side, and 1.8-m wide sidewalks. No paved shoulders or bicycle lanes were included in the design.

Using the BCI model, the bicycle LOS for the proposed route can be determined as follows. First, the projected AADT of 16,000 vpd must be converted into an hourly volume. The highest hourly volume on this roadway is during the peak hour with 10 percent of the AADT (1,600 vehicles) traveling in both directions during this hour. It is also known that the directional split during the peak hour is 70/30, i.e., 70 percent of the vehicles are traveling in one direction during the peak hour. Thus, 1120 vph (0.7 x 1600) is the directional volume to be used. Since this volume will be distributed across two lanes with 60 percent of the traffic in the curb lane, two final calculations are made to determine the lane volumes as follows:

Curb lane volume (CLV)

= 1120 x 0.6 = 672

Other lane volume (OLV)

= 1120 x 0.4 = 448

Table 18. Bicycle Compatibility Index (BCI) computations and levels of service (LOS) associated with the geometric design options in the example.

The truck traffic on the roadway was projected to be 2 percent of the AADT. Using the same assumptions for directional splits and lane distributions, the number of trucks per hour in the curb lane becomes 13 (0.02 x 672). From table 16, the adjustment factor (f_t)for this level of truck volume is 0.10.

Using this information and the other data provided, the BCI for the original proposed design was computed as shown in table 18. The calculated BCI was 4.71 which, based on the LOS criteria shown in table 17, results in a bicycle LOS E or a very low level of compatibility for bicycling.

Since this particular roadway presently accommodates a fair volume of commuting bicyclists and is an important link in the bicycle network, it is desired to provide bicycle LOS C or better. Thus, two optional designs are proposed that fit within the 20.0-m-wide right-of-way. The first option is the wide curb lane design in which the planting strip is eliminated and the curb lanes are increased to 4.6 m in width; all other dimensions remain the same. As shown in table 18, this design results in a BCI of 4.21, which is equivalent to LOS D and indicates a moderately low level of compatibility for bicycling. While this is an improvement, it does not increase the LOS to the desired level.

The second optional design incorporates a 1.2-m-wide bicycle lane, as shown in figure 22. Again, the planting strip has been eliminated and the original sidewalk width is maintained. The curb lane widths of 3.6 m are also maintained, but the interior lanes are reduced slightly to 3.4 m. The BCI for this option is computed to be 3.24, as shown in table 18. This value equates to LOS C, which indicates a moderately high level of compatibility for bicycling and meets the desired bicycle LOS requirements for the roadway.

This example was provided to illustrate the practical use of the BCI model in evaluating alternative designs to ultimately arrive at a design that could be considered "bicycle friendly." Other examples associated with various aspects of planning and design issues as well as detailed instructions on how to apply the model can be found in the companion report to this document, titled The Bicycle Compatibility Index: A Level of Service Concept, Implementation Manual.