Guide to Calculating Mobility Management Benefits Victoria Transport Policy Institute
This section examines various criticisms of mobility management. For more discussion see “Evaluating TDM Criticism,” in VTPI, 2006.
Critics sometimes claim that mobility management has been tried but failed, with statements such as, “Despite huge expenditures on HOV lanes, buses and other transportation alternatives, transit’s market share and carpooling have declined.” (GPPF,
. However, such criticism is often misplaced for the following reasons:
In most communities only a small portion of trips are directly influenced by specific strategies, such as commute trip reduction programs and HOV lanes. However, there are often significant travel changes by affected trips. For example, many HOV lanes carry far more peak-period travelers than general purpose lanes, and many of the passengers who ride new transit routes would otherwise drive alone. The relatively small total impacts reflect the low level of implementation.
Critics generally only consider one or two mobility management strategies. Comprehensive programs that include a combination of appropriate incentives (such as parking pricing or cash out) and improved travel options (such as significantly improved ridesharing and transit services) often have significant impacts.
Critics often misrepresent impacts, costs and benefits. For example, when critics claim that HOV facilities are underperforming they often use daily average rather than peak- period vehicle traffic counts. When they claim that transit trips are more costly than automobile trips, they are generally only considering a limited set of costs (such as just roadway costs, ignoring parking costs, vehicle costs and external costs such as congestion, accident risk and pollution emissions imposed on others), and ignore the large portion of transit costs that are justified by equity objectives (such as providing basic mobility during off-peak times and lower-density areas, and providing extra services such as wheelchair lifts). When all impacts are considered, a combination of incentives and investments in alternative modes often turn out to be the most cost effective way to address transportation problems and improve transportation in an area.
Critics sometimes assume that any reduction in vehicle travel harms consumers. However, many mobility management strategies involve positive incentives, such as improved transport options or financial rewards to reduce vehicle travel, as summarized in Table 26. Consumers only reduce mileage if they consider themselves better off overall. Even strategies that involve negative incentives, such as increased road and parking fees, benefit most consumers overall, because reductions in vehicle travel are offset by improved transport and land use options (for example, road pricing reduces bus and carpool congestion delays) and provides revenues. Only after all of these factors are considered is it possible to determine whether an individual is worse off overall.
Case studies in worksites that implement commute trip reduction programs, and cities that implement transit improvements and road pricing indicate that public support tends to increase for these strategies after they are implemented, indicating that most consumers consider themselves better off overall (“Success Stories,” VTPI, 2006)