When cost, community or environmental impact limit expansion of the transportation system, improving the management and utilization of the existing system becomes a primary strategy. Boulder is largely developed and will not grow outward due to its open space. Significant growth in business however, is projected for Boulder. This will require a balance between transportation improvements and demand management to serve the growing number of employees and customers while improving mobility and minimizing traffic congestion. Simply providing options is the start of the process; developing a desire to use the services is the logical next step to truly begin to manage traffic in Boulder.
How effective is TDM?
TDM effectiveness depends upon a variety of factors that extend well beyond the actual strategies implemented. For example, promoting transit works well in areas well served by the Community Transit Network, but not as well where frequencies are light. Other factors, such as aesthetically pleasing pedestrian environments and bicycle facilities provide an opportunity to promote these modes.
The TMO graphic (at right) identifies how effective a range of TDM services could be in certain areas. A low (basic) level of application only assumes base TDM services. The medium (enhanced) level is well represented by what is suggested in the TMP. The high (aggressive) level would include more aggressive measures, such as parking pricing.
Positive and Negative Incentives
TDM strategies manage the demand for transportation infrastructure and the use of modal options by using potential positive and negative incentives:
How effective can TDM be in reducing the number of those who drive alone?
Each TDM strategy has its own inherent opportunities and limitations. In general, TDM strategies complement each other for example, parking management helps encourage all core TDM options (i.e., transit, bicycling and walking, carpooling, vanpooling, and teleworking). In some situations, support strategies (i.e., incentives and subsidies, parking management and parking fees, rideshare matching) will only aid a few core TDM strategies.
Generally, TDM effectiveness can be summarized by the application of packages (per worksite). These are national effectiveness averages, as estimated by a reduction in single-occupant vehicle use per worksite in favor of the selected mode. Generally, packages are not cumulative, as the various TDM strategies employed at different levels of implementation will be somewhat repetitious. However, economies of scale also will enhance complementary modes.