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  • 1.  Vehicle Miles Traveled

    Posted 01-29-2017 09:24 PM
    Consideration of the VMT tax brings up three considerations that have not received much attention so far and one that has. I'll address the later one first: both federal and state governments have been remiss in not pegging the gas tax to inflation. Although the current inflation rate is low, the value of the dollar still decreases over time.

    Now for the other three considerations: one: miles driven by a vehicle does not correlate to the impact that vehicle has on pavement deterioration/condition. The key factor in designing pavement, other than underlying soil, are the number of large commercial trucks (i.e., 18-wheelers) that will use the road. One truck is equivalent to approximately 3000 cars on its impact to pavement life. Overloaded commercial vehicles, interstate buses, and some other vehicle types have even higher car equivalencies. Second: road maintenance does not provide a photo opportunity for politicians. Political decisions favor building roads were none exist or widening existing roads over maintenance. This favoritism is often driven by the development community wanting publicly-funded infrastructure for access to their projects. (As an aside, residential annexation by cities typically generates $.80 in tax revenue for every $1.00 spent by the city on infrastructure and services; not a good ROI.) Lastly, many states have diverted their existing gas tax revenues to pay non-roadway/highway related expenses. For example, Arizona funds the Department of Public Safety with gas tax monies that initially went to their Department of Transportation. Gas tax money is also used to supplement the cost of advertising alerting motorists to what gas and food options are at the upcoming exit.

    In summary, I don't believe a tax based on miles driven by passenger cars is the appropriate solution for infrastructure funding until the four items above are addressed.

    Kenneth Cooper P.E., F.ASCE
    Kenneth Cooper Engineering
    Hendersonville NC

  • 2.  RE: Vehicle Miles Traveled

    Posted 02-04-2017 11:05 AM
    The gas tax raises money and is easy to implement and conforms to public policy on carbon emissions.  Because it's so flexible and effective in raising money, and it's institutionalized, it should be the major funding source until other sources are worked out that address equity issues.  I agree with others on the effects of trucks, which are subsidized through having to design pavements and bridges to take their loads (mainly dynamic), and their effect on traffic.  Not mentioned, is that public transportation has a "standby" utility, like the telephone in that it's there for when convenient to use.  So "miles driven" is not a "sufficient" parameter.  We all know that rational solutions are limited by political/ideological factors.  As a final point, highways can also reduce the livability of cities and may make driving unappealing unless such factors are considered.

    David Hendricks P.E., F.ASCE
    Arvada CO