Drive-by Motor Vehicle Emissions:  Immediate Feedback in Reducing Air Pollution

Abstract

Using input from the public, a new type of vehicle emissions information system has been developed which utilizes an innovative variable message sign to display individual vehicle emissions information to passing drivers. Called the Smart Sign, the system merged highway messaging and on-road vehicle emissions sensing into a costeffective public information system. The Smart Sign used a combination of words, colors, and graphics to connect with its audience. During its operational test period the system proved to be a viable technical concept which can be operated dependably and safely in even high traffic areas (in excess of 1000 vehicles per hour). The system was subjected to a wide range of operating conditions including weather extremes (-20 to 100 °F, heavy rain, hail, snow) and between May 16, 1996 to May 15, 1997 recorded unattended emissions information of more than 3 million readings from an estimated 250 000 individuals. The ability to operate the system without constant human supervision has created a cost-effective messaging system capable of delivering real-time vehicle emissions information for a long term estimated cost of $60 000/yr or about $0.02 per test and demonstrated the potential for intelligent highways of the future to detect gross polluting vehicles. Using information from a companion license plate reading system a sample of 474 motorists (14% poor, 43% fair, and 43% good) were interviewed by telephone. Seventy-six percent of the weighted population had a favorable impression (5% unfavorable) of the Smart Sign with the majority (61%) expressing its informative nature as the main reason. Eight percent of the total sample planned to do something in response to the sign. Respondents in the "POOR" stratum (31%) were almost twice as likely to respond to the system as those in the "FAIR" stratum (16%) and five times as likely as those in the "GOOD" stratum (6%). Sixteen percent of the poor's (1.6% of the overall fleet) reported to have already taken corrective action as a result of the Smart Sign. This produces an estimate that more than 4000 voluntary repairs were made as a result of Smart Sign readings during the year.

A technology‐based global inventory of black and organic carbon emissions from combustion

“…However, even some simple measurements could assist in reducing the uncertainties. For example, remote‐sensing measurements such as those described by Bishop et al [2000] could assist in estimating the fraction of superemitters, contributing to understanding of gaseous emissions in addition to PM. However, the interpretation of these measurements needs refinement in order to attribute particulate matter to different vehicle types.…”

“… Lawson [1993] reported that 10% of the light‐duty vehicle fleet in California emitted 60 percent of the carbon monoxide, implying that the high‐emitting fraction averaged 13 times greater than the rest. Bishop et al [2000] reported over 3 million individual‐vehicle remote‐sensing measurements from the Denver area. From those data, we infer that “superemitters” are about 6% of the vehicles and, on average, emit about 17 times the CO of the remainder.…”

“…Second, there is a lack of relevant data on CO that could be used as a proxy. A large database of CO emission factors in various world regions is developing from remote‐sensing studies [ Bradley et al , 1999; Bishop et al , 2000], but so far these data have been designed to address gasoline vehicles. Further analysis of these data sets may allow a more expanded treatment of diesel emission factors.…”

“…Williams et al [1989]; Durbin et al [1999a]. m Hansen and Rosen [1990]; Lawson [1993]; Sagabiel et al [1997]; Durbin et al [1999b]; Lawson and Smith [1998]; Bishop et al [2000]. Note that some of these studies measure CO only.…”

Evaluation of Environmental Issues

“…An example of a technical project was an Intelligent Transport Systems (ITS) Operational Test project sponsored by the United States Department of Transportation/Federal Highway Administration (USDOT/FHWA), which was designed to support cleaner air by providing real-time tailpipe emissions information to the driving public. The operational test project consisted of the installation of an ITS system (Figure 1) that measured real-time tailpipe carbon monoxide (CO) emissions from passing vehicles, a variable message sign (VMS) that immediately presented the CO emissions levels to the motorists (Figure 2), and auxiliary support information services (Figure 3) such as a hotline and brochures (Bishop et al 2000;Bohren and Williams 1997). The ITS, a remote sensing information system (RSIS), uses a remote sensing device (RSD).…”