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Pittsburgh Area Lock Closure Externality Study

Larry Bray, Ph.D. University of Tennessee

Center for Transportation Research

Transportation Research Board Joint Summer Meeting

July 12, 2010 Minneapolis, Minnesota

Prepared for the The Tennessee Valley Authority

On contract to the U.S. Army Corps of Engineers

Study Team

• Tennessee Valley Authority– Chris Dager, MBA– Charles Beasley, MS– Arland Whitlock, PE

• College of Engineering, Civil and Environmental Engineering Department– Fred J. Wegmann, Ph.D.– Arun Chatterjee, Ph.D., P.E.– Terry L. Miller, Ph.D., P.E.

• Center for Transportation Research– Larry G. Bray, Ph.D– Matthew Cate, P.E.– Michael Murphree, M.S., systems analyst

Chickamauga Lock Methodology and Analysis Peer Reviewed

• Dr. Donald Jones at the Oak Ridge National Laboratory

• Chickamauga Lock analysis– Chatterjee, Wegmann, Jackson, and Bray.

“Effect of Increased Truck Traffic from Chickamauga Lock Closure”. Transportation Research Record (2001).

Purpose of the Study

• The study places annual dollar values on costs borne by society for both short and intermediate duration outages at Emsworth, Daschields,and Emsworth Locks.– Only diversions to truck traffic are considered

in this part of the broader study that also considers rail transportation.

Basic Methodology

• Congestion and speed are forecast in future years for a base case traffic volume and growth rate.

• Diverted cargo truck traffic due to lock outage is then introduced into the base traffic flows to estimate the traffic and social cost differentials due to lock closure.

Major Takeaway from the Study

• A relatively small amount of diverted traffic can have a large impact on a region already experiencing traffic congestion, especially at choke points such as tunnels and bridges.

• The diversions would have been more significant in Pittsburgh if the traffic had been more concentrated on particular routes.

Types of Externalities Considered

• Value of travel time (congestion)

• Highway safety• Fuel consumption• Air pollution

Resulting from increased vehicle miles traveled and highway congestion

Short and Long Term Closure Scenarios

• Furnished by Huntington District– Short term closure

• 60 days• 38 days for computation

– Long term closure• 180 days• 121 days for computation

Impacts are Monetized

• Dollar values are placed on the impacts with– AASHTO Red Book—User Benefit Analysis

for Highways– Environmental Protection Agency

• MOBILE6• BenMap

The Pittsburgh Study: Highway Component

• TVA surveyed the shippers and mapped the routes

• CTR drove the routes• CTR built Pittsburgh Traffic Impact Model• CTR developed parameter estimates• CTR used the model to develop the

forecast of lock closure diversion costs

TVA Surveyed the Shippers and Mapped the Routes

• Tons moving through docks (furnished by Corps, Huntington District)

• Identified where the tons are moving to or from• Hours and days of operation• Truck weight loadings• Routes• If route not given, Mapquest was used to route

the shipments through Pittsburgh—Allegheny, Beaver and Washington Counties

Diverted Tonnage & Routes

• 2.6 million non-coal total tons• 1.4 million coal—short run only• Tonnage converted to trucks are overlaid

on 124 links of which 42 are used for analysis. The others have no measurable impact on v/c ratios but were used in the safety and economic analysis.

Field Trip

• The critical links were driven by CTR to collect necessary data:– Link length, # of lanes, signals, speed limit, schools,

hospitals, no-passing zones, grade, truck speed restrictions, terrain, and access control

• One weight-limited bridge caused the rerouting of traffic resulting in the final critical links numbering 42

• Links were then tracked in PennDot videologs

Estimated Hourly Truck and Non-Truck Traffic Demand

• Average daily traffic (ADT) was taken from the PennDot GIS for each link.– The percentage of the link traffic accounted

for by trucks was also found here• ADT was allocated to hour of the day by

using the percentage of the state ADT that occurs at each hour of the day

Highway Capacity• Highway capacity is estimated for signalized and

non-signalized roads with equations referenced in TRB’s Highway Capacity Manual and The Bureau of Public Roads

• Volume to capacity ratio (V/C) is critical in estimating average vehicle speeds for non- signalized roads during each hour of the day

• All equations are documented in the draft report• Model calculates hourly average travel times

(hours per vehicle-mile) by link:T = 1/S, where S is average calculated speed

Fuel Consumption

• From the Red book, gallons per mile (gpm) depends on average speed: one function for trucks and one for non-truck traffic.

• Real cost of fuel is set at $4.00/gallon

Crash Costs from the Red Book

• For passenger cars and large trucks in cents per vehicle mile:– Fatal accidents– Injury (non-fatal accidents)– Property damage only– Sums to total cost in cents/vehicle mile

Air Pollution Methodology

• Annual VMT x emission factors = tons by type of pollutant

• Social costs = tons x cost to society per pollutant type

• Values created by referencing each scenario to the base case

Air Pollution

• EPA’s MOBILE6.2 produces grams per vehicle mile for 5 classes of pollutants for 30 years by 14 speed classes for both heavy trucks and other vehicles.

• Social cost per gram for these same categories of pollutants is generated by EPA’s BenMAP model (Environmental Benefits Mapping and Analysis Program)

MOBILE6

• MOBILE6.2 is an EPA product that estimates pollution from highway vehicles. The model accounts for emission impacts, accounting for vehicle emission standards, changes in vehicle populations and activity, and variation in local conditions such as temperature, humidity, and fuel quality.

Pollutants

• PM2.5 Particulate matter• Precursors to Particulate Matter

– NH3 Ammonia– NOx Nitrogen Oxides– SO2 Sulfur dioxide– VOC Volatile organic compounds

Distribution of Pollutants Through Time

• EPA assumes in MOBILE6.2 a very aggressive implementation of pollution standards

• Emission factors fall per VMT through time until in 2030 all standards are fully implemented

• CTR utilizes the 2030 values through the remaining years of the 51 year period

Foundation of BenMap

• Epidemiological studies quantify the health benefits of reducing air pollution

• EPA uses $6 million per life saved due to the reduction of pollution

• Benefits are keyed to two studies in major medical journals

• Benefits used by CTR are those of a 25% reduction in mobile sources (the minimum considered)

Air Pollution Cost per Ton of Pollutant per Year

(Source: BenMAP)

Particulate Matter $ 372,797Ammonia $59,780

Nitrogen Oxides $8,961

Sulfur Dioxide $27,088

Volatile Organic Compounds

$695

Traffic Forecast

• Forecast is linear-thus no compounding– Forecast is first determined, averaged over

the appropriate number of years, and then incrementally added to ADT at each year such that no compounding occurs.

– Three growth scenarios used in the study for resident traffic

• 0.55%, 1.07%, 1.60%– New trucks grow at 1.0%/year in each

scenario

Highways Heavily Impacted by New Trucks

• Carston Street area of 3rd street• Fort Pitt Bridge• I-279 Exit 5a to end of tunnel• Pa 22/Pa 30/I-279 Pa 22 to Exit 4a• McKeesport to Fleming Bridge• I-279 Fort Pitt Bridge to Fort Duquene Bridge to I-279• Neville Road

Cost Per Ton By Component Year 1

Short Term Closure

Long term Closure

Total $3.10 $3.45

Travel Hours $1.46 $1.66

Accidents $0.14 $0.16

Fuel $1.05 $1.16

Emissions $0.44 $0.48

Cost Per Ton By Component Year 25 – Short Term Closure

0.55% ADT Growth

1.07% ADT Growth

1.60% ADT Growth

Total $3.20 $4.09 $5.95

Travel Hours $1.76 $2.46 $4.08

Accidents $0.14 $0.14 $0.14

Fuel $1.26 $1.46 $1.71

Emissions $0.03 $0.03 $0.03

Percent Travel Time is of Total Cost: Short Run Scenario

% Growth Rate

Year 1 Year 25 Year 51

0.055 47.10 55.00 61.16

1.070 47.10 60.15 79.85

1.600 47.10 68.57 92.90