Common use of Mode Choice Clause in Contracts

Mode Choice. For mode choice, two of the most commonly used models are the multinomial logit and nested- logit models (▇▇▇-▇▇▇▇▇ and ▇▇▇▇▇▇, 1985). Similar to logit-based destination models, a multinomial logit mode-choice model hypothesizes that the probability for an individual to choose a particular mode for a trip of certain purpose depends on the ratio of the mode’s utility, expressed as a function of the mode’s characteristics (e.g., availability at the origin TAZ, travel time, cost, and convenience for the trip purpose), to the sum of utilities of all competing modes. The other commonly used mode-choice model, nested logit model, hypothesizes a nested structure, in which mode choice alternatives that share similarities are pooled together. The process of choosing a mode for a particular trip purpose is represented as a multistep decision. The probability of choosing an alternative within its nest of similar alternatives is given by the ratio of the mode’s utility to the sum of utilities of all alternative modes within the same nest. The probability of choosing a nest against other nests depends on the ratio of the nest’s utility, which is expressed as a composite of utilities of all alternatives within the same nest, to the sum of composite utilities of all nests. In current travel demand modeling practice, the use of either a multinomial or nested logit model is considered acceptable practice in all regions (VDOT, 2014). However, because transportation mode choices do exist in nested structures, the use of nested logit models is the most common practice. According to NCHRP Synthesis 514, 14 states were identified as using nested logit model, compared to only two states using multinomial logit (NASEM, 2017).

Mode Choice. For mode choice, two of the most commonly used models are the multinomial logit and nested- logit models (▇▇▇-▇▇▇▇▇ and ▇▇▇▇▇▇, 1985). Similar to logit-based destination models, a multinomial logit mode-choice model hypothesizes that the probability for an individual to choose a particular mode for a trip of certain purpose depends on the ratio of the mode’s utility, expressed as a function of the mode’s characteristics (e.g., availability at the origin TAZ, travel time, cost, and convenience for the trip purpose), to the sum of utilities of all competing modes. modes.‌ The other commonly used mode-choice model, nested logit model, hypothesizes a nested structure, in which mode choice alternatives that share similarities are pooled together. The process of choosing a mode for a particular trip purpose is represented as a multistep decision. The probability of choosing an alternative within its nest of similar alternatives is given by the ratio of the mode’s utility to the sum of utilities of all alternative modes within the same nest. The probability of choosing a nest against other nests depends on the ratio of the nest’s utility, which is expressed as a composite of utilities of all alternatives within the same nest, to the sum of composite utilities of all nests. In current travel demand modeling practice, the use of either a multinomial or nested logit model is considered acceptable practice in all regions (VDOT, 2014). However, because transportation mode choices do exist in nested structures, the use of nested logit models is the most common practice. According to NCHRP Synthesis 514, 14 states were identified as using nested logit model, compared to only two states using multinomial logit (NASEM, 2017).2017).‌