Travel Costs

Lecture 14October 16, 200212-706 / 73-359

Value - travel time savings

Many studies seek to estimate VTTS Can then be used easily in CBAs

Book reminds us of Waters 1993 (56 studies) Many different methods used in studies Route, speed, mode, location choices Results as % of hourly wages not a $ amount Mean value of 48% of wage rate (median 40) North America: 59%/42%

Government Analyses

Typically 40-60% of hourly rate in CBAsUS (FHA) 60% - Canada 50%Again, travel versus leisure important

Wide variation: 1:1 to 5:1!Income levels are important themselves

VTTS not purely proportional to income Waters suggests ‘square root’ relation E.g. if income increases factor 4, VTTS by 2

Introduction - Congestion

Congestion (i.e. highway traffic) has impacts on movement of people & goods Leads to increased travel time and fuel costs Long commutes -> stress -> quality of life Impacts freight costs (higher labor costs) and

thus increases costs of goods & services http://tti.tamu.edu/inside/hdv/programs/ama/

mobility/study/report.stm (TTI report)

Literature Review

Texas Transportation Institute’s 1999 Annual Mobility Report 15-year study to assess costs of congestion Average daily traffic volumes Binary congestion values

‘Congested’ roads assumed both ways

Assumed 5% trucks all times/all roads Assumed 1.25 persons/vehicle, $12/hour Assumed roadway sizes for 3 classes of roads Four different peak hour speeds (both ways)

Results

An admirable study at the national level

In 1997, congestion cost U.S. 4.3 billion hours of delay, 6.6 billion gallons of wasted fuel, thus $72 billion of total cost

New Jersey wanted to validate results with its own data

New Jersey Method

Used New Jersey Congestion Management System (NJCMS) - 21 counties total

Hourly data! Much more info. than TTI report

For 4,000 two-direction linksFreeways principal arteries, other arteries

Detailed data on truck volumes Average vehicle occupancy data per county,

per roadway type Detailed data on individual road sizes, etc.

Level of Service

Description of traffic flow (A-F) A is best, F is worst (A-C ‘ok’, D-F not)

Peak hour travel speeds calculated Compared to ‘free flow’ speeds A-C classes not considered as congested D-F congestion estimated by free-peak speed

All attempts to make specific findings on New Jersey compared to national

http://www.njit.edu/Home/congestion/

Definitions

Roadway Congestion Index - cars per road space, measures vehicle density Found per urban area (compared to avgs) > 1.0 undesirable

Travel Rate Index Amount of extra time needed on a road

peak vs. off-peak (e.g. 1.20 = 20% more)

Definitions (cont.)

Travel Delay - time difference between actual time and ‘zero volume’ travel time

Congestion Cost - delay and fuel costs Fuel assumed at $1.28 per gallon VTTS - used wage by county (100%) Also, truck delays $2.65/mile (same as TTI)

Congestion cost per licensed driver Took results divided by licenses Assumed 69.2% of all residents each county

Details

County wages $10.83-$23.20 per hour

Found RCI for each roadway link in NJ Aggregated by class for each county

RCI result:

Northern counties generally higherthan southerncounties

New YorkCity

TRI result:

Northern counties generally higherthan southerncounties

Avg annualDelay = 34 hours!

Almost a workWeek!

Effects

Could find annual hours of delay per driver by aggregating roadway delays Then dividing by number of drivers

Total annual congestion cost $4.9 B Over 5% of total of TTI study 75% for autos (190 M hours, $0.5 B fuel

cost) 25% for trucks (inc. labor/operating cost) Avg annual delay per driver = 34 hours

Future

Predicted to only get worse Congestion costs will double by 2015