Toll bridges lag state with old geometry, structural problems of toll not as bad (FOLLOWUP)

Toll bridges lag their state counterparts in the geometrics. They are much more liable to be "functionally obsolete." On the structural side the toll bridging - this is big bridges plus the smaller bridges along tollroads and turnpikes - rates slightly better than state DOT bridging.

7% of toll bridge nationwide has structural deficiency compared to 8.6% of state DOT bridging.

Toll bridging wins by number of states 15 to 8 in the structural comparison.

Toll bridging is better structurally than state bridging in: CA, CO, DE, FL, IL,LA, MD, MI, NJ, OH, OK, PA, TX, VA, WV.

State bridging is structurally better than toll in: IN, KS, ME, MA, NH, NY, OR, RI.

Toll bridging's lag behind state bridging is entirely in functional obsolescence or geometric deficiencies, and here the lag is spectacular: by area of bridge deck 35% of toll bridging is geometrically obsolete or functionally deficient compared to 16% of state bridging.

Only in one state is toll bridging better in geometry than state: CO. (E470, NW Pkwy are new!)

The following states have worse toll bridge in terms of functional obsolescence than state bridge: CA, DE, FL, IL, IN, KS, LA, ME, MD, MA, MI, NH, NJ, NY, OH, OK, OR, PA, RI, TX, VA, WV.

That's 22 to 1 in favor of the state's bridging.

Mind you a couple are close: TX, OH. So perhaps they should be in a Drawn category making it 20/1/2 state/toll/drawn.

Definitions

Structural deficiency is where there's serious structural deterioration going on, load factors reaching limits, and increased risk of breakages and collapse.

Functional obsolescence is issues summarized in the term deficient "geometry" such as:

- lanes narrower than modern standards
- overhead clearances less than current standards
- lack of breakdown shoulder
- sight distances less than current standards because of excessive curvatures sideways or vertically
- short diverge and merge lanes
- inadequate travel lanes for the traffic volumes

Breakdown shoulders were long deemed too expensive on bridges even when they were a standard for roads so any bridge built before the 1980s is likely to be lacking in breakdown shoulder.

Functional obsolescence or deficiency can affect safety and capacity. It means side barriers are closer, and there's nowhere to pull out of the traffic when there's trouble. It accentuates the delays caused by incidents, makes staging of resurfacing and repairs more difficult - more lane closures - and can add chokepoints or bottlenecks.

The bigger bridges tend to be toll bridges and they tend to be older.

In some areas virtually all the toll bridges are likely to be classed as functionally obsolete:

- NY-NJ crossings of the PANYNJ
- all the New York City toll bridges
- most of the Bay area bridges of BATA and the Golden Gate Bridge
- Philadelphia area bridges
- all of Maryland's toll crossings
- Louisiana's New Orleans crossings
- Rhode Island's bridges

The tollroads/turnpikes were mostly built before the big era of gas-tax funded freeway construction, and designed to the lower geometric standards of the time. Modernization has been patchy and partial.

The bridge inventory data is for Dec 2006, so it is quite recent but would not catch some improvements such as the new Susquehannna River bridge of the Penn Pike. An FHWA official tells us state DOTs do the reporting and are responsible for the accuracy or inaccuracy of the data. FHWA basically compiles the data from state DOT reports.

Errors in FHWA data

There are a few obvious omissions in the data:

- South Carolina is down as having no toll facility. It has the Greenville Southern Connector with a lot of bridges, plus the Cross Island Parkway on Hilton Head Island which has a decent bridge over the aptly named Broad Creek, a tidal estuary

- Georgia is listed as having no tollroads with bridging - GA400 has several long overbridges that qualify for rating

- Puerto Rico is listed as having no toll bridging - the biggest mistake in the list because it has a large heavily bridged tollroad network plus a toll bridge near San Juan airport

Basis for classification

FHWA tell us this is the basis for the classification of deficient which comes from here
http://www.fhwa.dot.gov/legsregs/directives/fapg/0650dsup.htm:

a. General Qualifications: In order to be considered for either the structurally deficient or functionally obsolete classification a highway bridge must meet the following:

Structurally Deficient -
1. A condition rating of 4 or less for
▪ Item 58 - Deck; or
▪ Item 59 - Superstructures; or
▪ Item 60 - Substructures; or
▪ Item 62 - Culvert and Retaining Walls.(1) or
2. An appraisal rating of 2 or less for
▪ Item 67 - Structural Condition; or
▪ Item 71 - Waterway Adequacy.(2)

Functionally Obsolete -

1. An appraisal rating of 3 or less for
▪ Item 68 - Deck Geometry; or
▪ Item 69 - Underclearances;(3) or
▪ Item 72 - Approach Roadway Alignment. or

2. An appraisal rating of 3 for
▪ Item 67 - Structural Condition; or
▪ Item 71 - Waterway Adequacy.(2)

c. Any bridge classified as structurally deficient is excluded from the functionally obsolete category.

Goethals posterchild

The posterchild for a functionally obsolete bridge is the PANYNJ's Goethals Bridge which links the New Jersey Turnpike near Elizabeth NJ to the Staten Island Expressway over the Arthur Kill tidal channel that divides Staten Island from mainland USA. Opened in 1928 it was designed at a time when travel lanes were typically 3.05m (10 feet) and the deck of this bridge with interstate designation I-278 is only 12.8m (42ft) kerb to kerb. 0.6m (2ft) is taken up in the center with a Jersey barrier leaving only 12.2m (40ft) for two travel lanes of 3.05m (10ft) each direction versus the modern standard of 3.6m (11'8").

An average 71k veh/day use the Gothals, about 9% of them trucks, many 2.6m (8.5ft) wide. (see pictures nearby).

PANYNJ has had a permitting process under way for a replacement bridge since 2004 and it is the largest capital works road project of the authority. But it's a snail's pace replacement. They don't have a preferred alternative or a preliminary enviro impact statement after nearly four years.

see http://www.goethalseis.com/

This is a follow-on article to http://www.tollroadsnews.com/node/3403

TOLLROADSnews 2008-02-19