Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
consideration, is that in the absence of pricing it becomes apparent the implicit or “shadow” price
road users really pay includes both the cost of travel time and unreliability they experience to use a
route. So in reality both these factors are influencing the allocation of road users on a network of
free roads. In the future, the free portion of the highway network will continue to have its use
governed by the costs of travel time and unreliability drivers expect and experience on each link.
These costs, as in the past, will not be reflected in the market place through a toll or other pricing
transaction. A major attraction of just using travel time and travel time reliability to allocate scarce
highway capacity to road users, is that every person has an endowment of 24 hours per day, and
the approach is equitable since the time resources each person has is the same,
Another option for bringing supply and demand into balance on highly congested roads are
reservation systems. Road users can reserve slots in a stream of traffic on the network, and in this
way the scarce capacity can be assigned. Reservation systems can be designed in many ways. They
can be based on a first-come-first served basis, a lottery, an auction, various pricing strategies, or a
combination. Depending upon the approach, various degrees of economic efficiency and equity
can be achieved.
A CONCEPT OF OPERATIONS Page 118