First Advisor

James G. Strathman

Date of Publication


Document Type


Degree Name

Doctor of Philosophy (Ph.D.) in Urban Studies


Urban Studies and Planning




Local transit -- Oregon -- Portland Metropolitan Area -- Safety measures, Bus drivers -- Behavior -- Evaluation, Tri-County Metropolitan Transportation District of Oregon, Bus accidents -- Oregon -- Portland -- Prevention



Physical Description

1 online resource (viii, 174 p.) : ill. (some col.)


The incidence of bus crashes in the US have been trending upwards, with accident, injury and fatality rates increasing 171%, 37.8%, and 5.1% respectively, between 2003 and 2007. Reversing the upward trend is an important objective of both transit providers and the society in general. This study introduces an operator-based safety methodology that utilizes data recovered from transit Intelligent Transportation Systems (ITS) technologies and related systems to identify and assess factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland, Oregon metropolitan region. The analysis specifically focuses on collision, non-collision and total incidents, as well as on preventability of incidents that occurred between 2006 and 2009. Regression analysis established that bus operator age, experience, short duration absenteeism from work, operator's work span and variability in daily work span/assignments are empirically correlated with bus safety incidents. In addition, schedule adherence pressures and bus lift operations are also related to safety incidents. The other factors that influence safety performance are operators' responsive action events and customer complaints about unsafe bus operation. These findings make some contributions to the understanding of the factors that are empirically related to the frequency of safety incidents as well as offer insights into operation practices and policies that hold promise for reducing bus safety incidents.


In Copyright. URI: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).


Nohad A. Toulan School of Urban Studies and Planning

Persistent Identifier