Vehicle miles traveled

Emissions of CO in the United States peaked in the late 1960s, but have decreased consistendy since that time as transportation sector emissions significandy decreased. Between 1968 and 1983, CO emissions from new passenger cars were reduced by 96% (see Exhaust CONTUOL, automotive). This has been partially offset by an increase in the number of vehicle-miles traveled annually. Even so, there has been a steady decline in the CO concentrations across the United States and the decline is expected to continue until the late 1990s without the implementation of any additional emissions-reduction measures. In 1989, there were still 41 U.S. urban areas that exceeded the CO NAAQS on one or mote days per year, but the number of exceedances declined by about 80% from 1980 to 1989. Over the same time period, nationwide CO emissions decreased 23%, and ambient concentrations declined by 25% (4). 

APRAC-3 contains the emission factor computation mcdiodology and treats traffic links in die primary network with low vehicle miles traveled as area sources. 

Regional congestion pricing of 0.15 per mile may yield a vehicle miles traveled (VMT) reduction of about 5.0 percent and trip reduction of 3.8 percent ... 

The data in Tables 10.27 and 10.28 also show that the percentage of in-use, gasoline-fueled noncatalyst light-duty automobiles dropped from 44% in 1982 to 8% in 1993 and the percentage of their vehicle miles traveled went from 33% to only 4% during that period. Furthermore, while diesel cars accounted for only 1.9 and 1.5% of the in-use light-duty automobiles in 1982 and 1993, respectively, they were responsible for 45 and 40% of the total auto exhaust particulate matter. Par-... 

Percentage of in-use light-duty automobiles Percentage of vehicle miles traveled Relative percentage of exhaust emissions of PM by light-duty automobiles Emissions of PM by light-duty automobiles (tons / day)... 

FIGURE 16.40 Calculated ozone production per vehicle mile traveled for various car-fuel combinations. RFG = reformulated gasoline M85 = 85% methanol, 15% gasoline E85 = 85% ethanol, 15% gasoline CNG = compressed natural gas (adapted from Black et al., 1998). 

Ihe specific information used to provide estimates of activity levels varies with the emission source sector being examined. For utilities, fuel use is desired. For the industrial sector, information on fuel use alone is not adequate since many industrial process emissions do not result from fuel combustion. Usually, some approximation for product output, such as estimates of value added or earnings, is often used. For motor vehicle emissions, estimates of vehicle miles traveled is more useful than fuel use because most emissions are unrelated to vehicle efficiency, i.e., a small car emits about the same amount of pollution per mile as a larger car. 

In the committee s analysis, both the number of new cars sold and the total vehicle miles traveled increase at 2.3 percent per year, consistent with the Energy Information Administration s (EIA s) Reference Case forecast of growth in vehicle miles traveled for light-duty vehicles.5 (This forecast rate of increase is consistent with recent historical trends, but the committee recognizes that it could be subject to alteration by many factors.) The total vehicle miles traveled for each type of car is proportional to the number of each type on the road, adjusted so that new cars are assumed to be driven more than older cars are. 

New car sales have grown less rapidly. But the committee s estimates are most sensitive to vehicle miles. Therefore, the model was calibrated to vehicle miles data from the EIA. Estimates were made for year 2000 vehicle miles traveled to be 2523 billion miles for light-duty vehicles, using the estimate from Annual Energy Outlook 2003 (EIA, 2003). 

The number of vehicle miles traveled doubled between 1970 and 1990 to 2.2 trillion miles, so these gains in fuel efficiency were mostly offset. The improvement in efficiency was mainly due to legislation passed in 1975 that established Corporate Average Fuel Economy or CAFE rules. This allowed automakers to produce any kind of car as long as all the vehicles when averaged meet the MPG standards set by the government. 

It is estimated that in 1994 there were 147,000,000 light-duty motor vehicles in the United States, 48,000,000 trucks light-duty), and 676,000 buses. Total vehicle miles traveled were estimated as X 10 . with 1.4 X 10"gallons of gasoline consumed. 

The formulation of emission factors for mobile sources, the major sources of VOCs and NO, is based on rather complex emission estimation models used in conjunction with data from laboratory testing of representative groups of motor vehicles. Vehicle testing is performed with a chassis dynamometer, which determines the exhaust emission of a vehicle as a function of a specified ambient temperature and humidity, speed, and load cycle. The current specified testing cycle is called the Federal Test Procedure (FTP). Based on results from this set of vehicle emissions data, a computer model has been developed to simulate for specified speeds, temperatures, and trip profiles, for example, the emission factors to be applied for the national fleet average for all vehicles or any specified distribution of vehicle age and type. These data are then incorporated with activity data on vehicle miles traveled as a function of spatial and temporal allocation factors to estimate emissions. 

Fatal Crashes — From 2001 to 2010, the number of large trucks involved in fatal crashes dropped from 4,832 to 3,484 — down 28 percent. The number of large trucks involved in fatal crashes per 100 milhon vehicle miles traveled also declined in these years from 2.31 to 1.22. 

Injury Crashes — From 2001 to 2010, the number of large trucks involved in injury crashes per 100 million vehicle miles traveled declined by 29 percent. 

CO and Particulates. For CO and PM 10, Title I required oxygenated gasoline in the winter for areas where the ambient CO level exceeded 9.4 ppm. For areas where CO exceeded 12.7 ppm, enhanced I/M and predictions of vehicle miles travelled (VMT) were required. As in severe ozone areas, serious CO areas had to impose TCMs. Areas where PM 10 levels exceeded EPA limits had to reach compliance by December 1994, with possible extensions to 2001. Moderate PM 10 areas had to adopt RACT, and serious areas had to adopt BACT (best available control technology). 

Puentes, R., Tomer, A. (2008). The Road... Less traveled An analysis of vehicle miles traveled trends in the U.S. Washington, DC Brookings Institution. 

Figure 1-4. Fatalities per vehicle miles traveled in different countries (from 2001-2003 IRTAD data, with permission, collated by Link, 2006).

Fatality Rate per 100 Million Vehicle Miles Traveled... 

Depending on the BASIC, number of power vmits and vehicle miles travelled. 

Unsafe Driving BASIC this term is not used since other data elements (power units, vehicle miles traveled) are used as the normalizer in the CSA Methodology. 

The Unsafe Driving BASIC uses relevant violations of the Federal Motor Carrier Safety Regulations (FMCSRs) recorded during roadside inspections and entered into MCMIS by enforcement personnel. The methodology was revised to remove the relevant inspections as a normalizing factor and replaced to include vehicle miles traveled and average power units. 

---