Accident Experience Involving Soundwalls
Accident Experience Involving Soundwalls

Author: L. L. Seamons

Publisher:

Published: 1990

Total Pages: 78

ISBN-13:

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This report presents the results of a before-and-after study of soundwall installations which indicates that the installation of soundwalls did not significantly increase the total accident rate. The study involved comparing the accident experiences among groups of soundwall installations; a group being defined by base or protection type and distance from the edge of the traveled way. Soundwall accidents were also compared with all urban freeway accidents. All available collision reports were read and examined for angle of impact. Fatal collision reports were further examined for causative factors. The final conclusions are that the data in this report does not conflict with Caltrans' newly revised soundwall base type policy and actually lends support. The support is qualified because of the small data samples available for some aspects of the study.

Accident Experience Involving Soundwalls
Accident Experience Involving Soundwalls

Author: L. L. Seamons

Publisher:

Published: 1990

Total Pages: 78

ISBN-13:

DOWNLOAD EBOOK

This report presents the results of a before-and-after study of soundwall installations which indicates that the installation of soundwalls did not significantly increase the total accident rate. The study involved comparing the accident experiences among groups of soundwall installations; a group being defined by base or protection type and distance from the edge of the traveled way. Soundwall accidents were also compared with all urban freeway accidents. All available collision reports were read and examined for angle of impact. Fatal collision reports were further examined for causative factors. The final conclusions are that the data in this report does not conflict with Caltrans' newly revised soundwall base type policy and actually lends support. The support is qualified because of the small data samples available for some aspects of the study.

Evaluation of Operational Efficiencies, Cost, and Accident Experience of Four Phase Single Point Urban Interchanges
Evaluation of Operational Efficiencies, Cost, and Accident Experience of Four Phase Single Point Urban Interchanges

Author: Jim C. Lee

Publisher:

Published: 2002

Total Pages: 218

ISBN-13:

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This research compares two interchange types, the Tight Urban Diamond Interchange (TUDI) and the Four Phase Single Point Urban Interchange (40SPUI). The 40SPUI is referred to in this report as a Single Point Urban Interchange with Frontage Roads (SPUI/F). The objectives of this research were to: (1) evaluate the SPUI/F based on available accident data and conflict analysis techniques, right-of-way and construction costs, and operating efficiency; (2) compare the performance of the SPUI/F and the TUDI; (3) evaluate current SPUI/F design assumptions and operation and recommend design and/or operational changes to enhance performance; and (4) evaluate the interchange form selection (pre-design) process and recommend changes where appropriate. The research found no significant difference in the safety aspects of the two interchange types. The SPUI/F generally did not perform as well operationally as the TUDI, with increased SPUI/F delay as the distance between frontage roads increased.