[Fracture Design A Winter Tale Zippy
Addison Mauldin
As part of Hispanic Heritage Month, Felipe Luyanda-Andino, a highway research engineer at the Federal Highway Administration's (FHWA) Turner-Fairbank Highway Research Center (TFHRC), paid a visit to the students at Cardozo High School in downtown Washington, DC on Oct. 15. His purpose? To encourage young Hispanics and other minorities to consider careers in the transportation field.
Luyanda-Andino visited Cardozo as part of a program sponsored jointly by the FHWA and the Department of Transportation's (DOT) Research and Special Programs Administration (RSPA) celebrating Hispanic Heritage Month. This year's national theme for Hispanic Heritage Month, "Paving the Way for Future Generations," lent itself well to Luyanda-Andino's visit as he educated students about the way transportation affects their lives and discussed potential career opportunities. Fluent in both English and Spanish, Luyanda-Andino gave two presentations-one in English and one in Spanish-at Cardozo, a school with a multi-cultural background.
Inquisitive Cardozo students eager to learn more about transportation quizzed Luyanda-Andino on a number of transportation issues, from gas prices to driver's education courses to roadway construction issues to traffic modeling.
Luyanda-Andino also provided students with information about the Summer Transportation Institute, a program open to high school sophomores and juniors throughout the country. The program, which runs four to six weeks, is jointly coordinated by the DOT and universities across the country and provides participants with in-depth tours of transportation facilities and information on various aspects of transportation and how it affects their daily lives. The program is designed to encourage young people to consider careers in transportation.
Promoting Federal Highway Administration (FHWA) programs and activities needs people with well-developed communications skills to engage the media. Recognizing the need to nurture those skills in their own staff, the Planning and Environment Core Business Unit (CBU) and the Research, Development, and Technology Service Business Unit (SBU) in the Washington, DC area engaged Steve Moler, Western Resource Center public affairs specialist, to teach a media training course. This full-day course, tailored to meet FHWA needs, teaches communications techniques for use in interviews and other public outreach events.
Moler stressed that successful media relations keeps the public better informed about what FHWA does. Using appropriate media techniques helps FHWA stay "on message" and maintain a positive agency image. Course exercises taught participants to prepare for both planned and spontaneous interviews by developing main message points from which to generate sound bites and quotes, a strategy that focuses and controls the interview process to better handle challenges from reporters.
Participants road-tested their skills in mock interviews that were critiqued by other participants. While these lessons were specifically designed for speeches and media interviews, the techniques learned in these mock interviews would enhance any speaker's ability to communicate, no matter what the situation.
Carin Michel of FHWA's Eastern Resource Center created both the training course and its accompanying manual, which serves as media training guidelines for FHWA. Michel and Moler have taught this course in the field and at headquarters. Queries about the course or requests to schedule a training session can be directed to Carin Michel at (410) 962-2530 or via e-mail at carin....@fhwa.dot.gov.
Recently, representatives from several transportation agencies and stakeholders in the New York metropolitan area gathered to investigate the potential for an innovative pricing strategy developed by the Federal Highway Administration (FHWA) to manage demand on the region's roadways. The strategy, called "FAIR lanes," or "Fast and Intertwined Regular" lanes, seeks to alleviate public concerns about conversion of currently free lanes to value-priced lanes.
FAIR lanes involve separating congested freeway lanes into two sections-Fast lanes and Regular lanes-using plastic pylons and striping. The Fast lanes would provide improved transit using new "para-transit" and limousine-type services, and would be electronically tolled, with tolls set in real time to limit traffic to the free-flowing maximum. Motorists are advised of the toll rate changes through electronic message boards located in advance of the entry points to the Fast lanes. In the Regular lanes, constricted flow would continue; however, drivers with electronic toll tags would be compensated with credits. Credits could be used as toll payments on days when they choose to use the Fast lanes or as payment for transit and para-transit services, which would be subsidized using toll revenues. The credits would compensate motorists for giving up their right to free use of the lanes converted to Fast lanes.
New York is discussing this innovative pricing concept because FAIR lanes would carry many more commuters on the existing highway infrastructure during rush hours, improving the ability of its transportation system to accommodate job and economic growth. Commuters would have increased choices and the region would have a new source of revenue to subsidize improved transit and para-transit services and ridesharing programs. And there would also be the potential for significant reductions in overall delay, pollutant and greenhouse gas emissions, and energy consumption.
FAIR lanes could provide an equitable, financially feasible, and economically efficient strategy to meet the transportation needs of the New York metropolitan area. The fact that many vehicles in the New York area are already equipped with electronic transponders may be a plus toward making the concept feasible. Many existing freeways and free bridges were suggested as possible candidates for an immediate demonstration of the concept. It was also suggested that, in the longer term, the region could use the concept to manage new capacity that is proposed for existing freeways.
Participants discussed possible public reaction based on the reaction of solo-driver focus groups held prior to the symposium. The focus groups liked the concept primarily because of the variety of commuting choices that they would have. They did not seem concerned about an existing lane being taken away from them for conversion to a Fast lane. Forum participants agreed, however, that overcoming political and public resistance to new tolls would not be easy.
The forum was co-sponsored by the Eno Transportation Foundation, the New York Metropolitan Transportation Council, and FHWA. The Eno Transportation Foundation is preparing a report on the forum for FHWA. For more information, contact:
On December 13, 2000, the Hoan Bridge, which carries I-794 over the Milwaukee River, failed, causing immediate closure of the interstate highway. The forensic evaluation team, led by the Federal Highway Administration's (FHWA) Office of Infrastructure Research & Development (R&D), included personnel from the Wisconsin Department of Transportation (WisDOT), Lichtenstein Engineers, Lehigh University, and Northwestern University. The team determined that the bridge failure was caused by a brittle fracture in the girder webs where the lateral bracing system was connected. Normally, this type of failure can only occur when fatigue damage exists and the material toughness is not sufficient to prevent fracture initiation. However, these factors were ruled out early in the investigation. Extensive material properties testing at the FHWA Structures Laboratory showed that the material properties were good, while an electron microscope examination of the failure at Lehigh University showed no evidence of fatigue.
The reason for the failure became apparent following a detailed three-dimensional nonlinear stress analysis that was performed by FHWA researchers. The results indicated that the particular detail geometry present in the Hoan Bridge created an unusual triaxially constrained stress state that made the bridge particularly susceptible to fracture. In fact, this finding represented a new failure mode for steel bridges that had never been previously documented. Once the problem was identified, the forensic team then designed a retrofit to modify all the vulnerabilities and restore the bridge to full service. The total cost of the Hoan Bridge retrofit was about $7million, compared to an estimated cost of $40 million to replace the bridge entirely.
Early in the investigation of the Hoan Bridge failure, FHWA's Office of Bridge Technology tried to determine whether other bridges were vulnerable to similar types of failure. Several hundred bridges were identified as being of the same general type and having the same design features as the Hoan. Fortunately, research is demonstrating that most of these bridges are not vulnerable to constraint-induced fracture. FHWA has issued a technical memorandum to all 50 States that offers some guidance in identifying potential problems in these structures. In fact, a bridge on I-64 in East St. Louis was identified as being another potential case of constraint-induced fracture. This structure is currently being retrofitted to eliminate any chance of failure during the coming winter. FHWA continues to research the problem and to help States identify bridges that may be facing this problem.
The Hoan Bridge Investigation Team was an effective partnership among FHWA, WisDOT, and several universities and consultants. The team cooperated to rapidly restore the Hoan Bridge to service and to identify any other potential safety concerns for other bridges. Their cooperative efforts have resulted in several awards, including the Secretary of the U.S. Department of Transportation's "Thanks a Million" award and the Federal Highway Administrator's "Strive for Excellence" team award.
DataPave 3.0, a software program that provides quick and easy access to most of the data from the Federal Highway Administration's (FHWA) Long Term Pavement Performance (LTPP) program, is now available.
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