Typically, drivers simply put small electronic tags, called transponders, on the windshield inside their cars. In conjunction with using the transponder, they open an account with a toll operator. Tolls are then collected as the tag is read at normal highway speeds by electronic scanners suspended from gantries above the highway. Motorists ensure adequate funding is available in their accounts by linking their accounts to their credit card accounts or through a quick call, trip to a kiosk or office, or visit to a web site. Tags may emit a signal warning consumers when their account is running low, or they may be informed through messages beamed to them as they go by a toll collection point.
With dynamic pricing, tolls are continually adjusted according to traffic conditions to maintain a free-flowing level of traffic. Under this system, prices increase when the tolled lane(s) get relatively full and decrease when the tolled lane(s) get less full. The current price is displayed on electronic signs prior to the beginning of the tolled section. This system is more complex and less predictable than using a fixed-price table, but its flexibility helps to consistently maintain the optimal traffic flow. Motorists are usually guaranteed that they will not be charged more than a pre-set maximum price under any circumstances.
This is handled in several ways. Of course, clear signage is used to show drivers which lane(s) or route to use to avoid the toll. This avoids most of these kinds of problems. Some systems also allow drivers to pay via credit card after-the-fact by calling a toll-free line. Some project sponsors simply let drivers use the tolled lane(s) at no charge the first few times. For instance, a letter may be sent to a non-paying driver identified based on matching of a photo of license plates with State vehicle registration databases. The letter would explain that if the driver wants to continue to use the facility, he or she should get a tag or risk a fine, but that initial usage is being allowed at no cost. The operator of an all-electronic toll facility in Toronto, Canada, simply bills such motorists for the cost of the toll plus an administrative fee. Through these kinds of steps, the chances of tourists, occasional visitors, or inadvertent users being penalized are minimized.
All of the operating pricing projects in the United States and more than 250 other toll facilities across the country use electronic toll collection (ETC). Tolling agencies have devised a method to protect the public's privacy by linking the transponder and the driver's personal information with a generic, internal account number that does not reveal the driver's identity and that is not disclosed to other organizations. Also, a motorist can open an anonymous account if he or she so chooses.
Prices will vary from project to project due to supply and demand, as well as other regional factors. If all lanes on an existing toll-free facility are priced, charges will be much lower, because there will be more "supply" of premium free-flowing traffic lanes, thus lowering the market-based price that must be charged to fully utilize the available capacity. Some projects do use a preset schedule of tolls. This has the advantage of being predictable and simple. With dynamic pricing, the toll fee is adjusted in real-time until optimal traffic flow is achieved. For example, the express lane fees for an 8-mile section in San Diego typically range from $1 to $4.
Results from surveys conducted for projects in operation show that drivers of all income levels use priced express lanes. Although many low-income users don't choose to use the tolled facility every day, they support having the option. For instance, a low-income parent racing to avoid the financial penalty associated with being late for pick-up at a day care facility, or for work, is often pleased to have the option of paying a fee to bypass gridlock in the regular lanes. In fact, a high level of support for San Diego's HOT lanes comes from the lowest income users (70 percent support). Moreover, low-income bus riders may benefit significantly from toll-financed transit improvements. Finally, a well-designed value pricing plan can be less burdensome to low-income citizens than current systems that are based on regressive taxes, such as car registration fees, sales taxes and the gas tax. For example, a proposal for pricing the San Francisco-Oakland Bay Bridge included life-line discounts for low-income motorists. The Bridge also currently provides free service for carpool vehicles during rush hours.
If road pricing enables reductions in current regressive fuel tax rates, low-income drivers will be better off, especially if the quality of public transport is improved and free alternative roads are available for those who do not choose public transport.
For more information on equity towards low income motorists, see the one page brief Congestion Pricing: Equity and the white paper Low-Income Equity Concerns of U.S. Road Pricing Initiatives
The prices road users currently face include only the value of their own travel time plus vehicle operating costs (including a small part that represents fuel taxes and occasional tolls). But the costs they impose during peak travel hours also include the value of the delays they impose on other users by slowing travel speeds. Speeds slow until the delays that vehicles impose on one another temporarily balance demand and supply, but only by deterring travelers (and shipments) whose time is most valuable, while wasting large amounts of others' time. Besides wasting their own and others' time, drivers sitting in congested traffic also impose pollution costs not covered by gas taxes.
Despite the magnitude of these costs imposed on others, rush hour vehicle users are currently not charged for these costs. Thus, separate congestion charges are appropriate. Gas taxes paid by a motorist amount to just two cents per mile driven. To avoid the claim of "double taxation," gas taxes already paid can be tallied separately and reimbursed to the driver, as is already done for toll road users in a few States.
It is true that when toll rates are raised on tollways, some drivers do divert to free alternatives. However, when pricing is introduced on previously congested highways, some traffic may actually be reduced on parallel arterials because certain travelers who were previously deterred by freeway congestion may shift back to the priced highways once congestion is eliminated and throughput has increased (as explained in an earlier section). Also, introduction of tolls during rush hour will be accompanied by expansion of transit capacity and continued availability of HOV options, so that some solo drivers will use transit or carpool rather than divert to free roadways. And, if rush hour toll revenues are used to pay for freeway widening, the expanded freeway will be able to carry even more traffic, and will further reduce traffic on parallel free arterials.
On average, over half of peak period drivers in metropolitan areas are not commuting 1. In other words, there is far more schedule flexibility than commonly understood. Moreover, the rise of the internet, pda's and telecommuting are providing employees with unprecedented flexibility to work outside the four corners of their offices. Giving people the option and incentive to shift trip times even 30-45 minutes can significantly reduce congestion. It is expected that employers would also respond to congestion pricing by offering employees more work schedule options.
1 Federal Highway Administration - National Household Travel Survey (NHTS) Briefs (PDF, 42KB)
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