| dc.description.abstract | As managed lane (ML) prevalence increases in the United States of America, it is important to understand travel behavior in ML settings (i.e., lane choices and carpooling decisions). Socio-demographic and trip data, along with travel time and toll, have been commonly used in this endeavor. However, there are some travelers who pay to use the ML despite there being little to no improvement in travel time over the adjacent general purpose lanes (GPLs). This gives rise to the possibility that psychological traits are a greater influence on ML use than even travel time savings for some travelers.
This research examined this issue through a set of largely transportation-framed psychological items. After an initial creation and refining process, 25 psychological items were included in a survey advertised in five ML study areas (Seattle, Salt Lake City (SLC), Los Angeles, Washington, D.C. (DC), and Minneapolis (Minn)). Dbefficient (DBE) and adaptive random (AR) designs were used to develop the attribute levels for the stated preference (SP) questions. The DBE design resulted in a higher adjusted rho square value and a higher overall percent correctly predicted value for a given model than the AR design; however, the AR design resulted in a higher carpool express lane (CP-EL) alternative percent correctly predicted value for a given model, and less non-trading and lexicographic behavior. In addition to psychological items, trip and demographic questions, and three SP questions were included in the online survey.
Based on mixed logit models created from responses obtained from SLC, Minn, and DC, better models (in terms of adjusted rho squared value and percent correctly predicted values) were obtained via the creation of psychological item models, when compared to their psychological scale or trip and demographic model counterparts. Likewise, combined models involving psychological items and trip and/or demographic data performed even better. This information may be useful for traffic and revenue estimating firms interested in potentially including psychological items in future ML surveys intended to facilitate better estimation of ML use.
Those who agree that “the coordination involved with carpooling is more hassle than it is worth” had a lower likelihood of selecting the carpool on the general purpose lane (CP-GPL) alternative than the drive alone on the general purpose (DA-GPL) alternative. Likewise, they had a lower likelihood of selecting the CP-EL alternative than the DA-GPL alternative. The same results were found for those who “do not like relying on others for rides.” Those who agreed that “Unless there is no traffic on the freeway, I choose the express lane since traffic could become congested at any time” had a higher likelihood of selecting the drive alone on the express lane (DA-EL) alternative than the DA-GPL alternative. Respondents who said that “When buying fuel for my car, I use the most convenient gas station and do not pay much attention to price” had a higher likelihood of selecting the DA-GPL alternative than the CP-EL alternative, and had a higher likelihood of selecting the DA-EL alternative than the DA-GPL alternative. The opposite was found for those who “cannot understand why someone would pay to use the express lanes when the general purpose lanes are available for free, especially when it may or may not save time”. Those who indicated that “I only choose to use the express lane if the general purpose lanes seem crowded” had a lower likelihood of selecting the DA-EL alternative than the DA-GPL alternative. | en |
