Utility is a mathematical description of how favorable an option is, relative to other options. Utilities are unit-less, and sometimes expressed as values between 0 (no utility) and 1 (highest utility). Sometimes, utilities are expressed as negative numbers to represent the burden of an action. For example, the utility for taking the bus can be more negative than the utility for taking a car in a mode choice model to express the potential added burden of waiting for the bus, transferring, and longer travel times on the bus, as applicable to the specific conditions.
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