The accessibility-based model’s estimates of trips by mode are generated by applying the mode choice models - estimate based on regional household survey data - to accessibility scores and household characteristics. The resulting estimates generally reflect the trends and tendencies revealed in the survey records. However, when compared to mode shares generated by the regional travel demand model, some discrepancies were observed. Notably, the accessibility-based model tended to estimate higher utilization of transit and non-motorized modes than the regional model.

To ensure consistency between the two modeling frameworks, the accessibility-based mode choice estimates were factored to more closely approximate the regional model’s outputs. The factors (called “K factor” in this analysis) were calibrated such that the LRTP scenario outputs from the accessibility model would resemble the corresponding estimates generated by the regional model. These factors were then applied in the same manner across all scenarios.

Below are several relevant notes for understanding, applying, and interpreting the K factors.