This paper explores the safety consequences of increasing truck driver pay. The test case the aut... more This paper explores the safety consequences of increasing truck driver pay. The test case the authors examine involves a large over-the-road truckload firm that on February 25, 1997, raised wages an average of 39.1%. An analysis that controls for demographic and operational factors, including prior driving experience and experience acquired on the job, suggests that for drivers employed during the lower pay regime and retained in the higher pay regime, crash incidence fell. A higher pay rate also led to lower separation probability, but this indirect effect only translated into fewer crashes by increasing the retention of older, more experienced drivers. These findings suggest that human capital characteristics are important predictors of driver safety, but that motivational and incentive factors also are influential. *Daniel A. Rodríguez is Assistant Professor of City
This report develops a comprehensive understanding of the truck-safety problem from the perspecti... more This report develops a comprehensive understanding of the truck-safety problem from the perspective of: 1) Roadway hazards, involving analysis of truck-involved crashes in work zones; 2) Socio-economic and driver occupational factors, involving examination of driver and work characteristics on truck crash occurrence and frequency. More specifically, the study is split into two parallel but complementary efforts, one relying on Highway Safety Information System crash and road inventory data and another looking at a longitudinal dataset of crashes, truck-driver characteristics and occupational factors obtained from a major for-hire truck-carrier. Two manuscripts resulting from each parallel research effort are included in the body of the report. The first effort analyzes how work zone attributes (such as type of work zone, presence of warning signs and cones, type of activity in the work zone, location of the crash in the work zone, construction impact of the wok zone on the roadway a...
The contents of this report reflect the views of the authors who are responsible for the facts an... more The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation. Report for MOU 363
These results translate into an elasticity of-0.31 for local accessibility and 0.44 for proximity... more These results translate into an elasticity of-0.31 for local accessibility and 0.44 for proximity-related effects. Based on a comprehensive literature review, this is the first empirical study in recent decades that consistently estimates evidence regarding the nature and magnitude of accessibility and proximity-related impacts of BRTs. Such evidence has a wide range of practical applications, from determining the usefulness of innovative land-based tax instruments that hinge on the capitalization of positive busway effects, to informing policy-makers about the land development consequences of transportation infrastructure alternatives.
Advanced Traveler Information Systems are becoming an integral part of urban transportation syste... more Advanced Traveler Information Systems are becoming an integral part of urban transportation systems. This paper discusses issues related to how people access, acquire and use travel information. The perceived benefits and willingness to pay for dynamic information are discussed. Empirical evidence from a major field operational test is examined to answer questions about why, how and who uses travel information. Empirical evidence suggests that information helps travelers to switch routes and departure time. The potential for information benefits is perhaps higher in cases of unexpected incidents. However, only one-third of the Target survey respondents changed their travel decisions in response to the incident. While this is a significant number in terms of demand reduction due to information, perhaps the full benefits of dynamic information are not realized because the quality of information available in just such situations is relatively low. New information media can focus on var...
Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the t... more Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the transport implications of these policies have been overlooked. This paper examines the impact that containment policies have on population density and vehicle miles travelled per capita. An empirical analysis is conducted, relying on a fixed-effects model for panel data for the largest 25 metropolitan areas in the US during the 1982 –94 time-period. Because the outcomes are endogenously related, instrumental variable regression is used to test hypotheses about the effect of the presence and age of containment policies on travel. The findings suggest that local containment policies and state-level involvement in enabling or mandating growth management are associated with higher population density and more miles travelled. The results uncover unanticipated relationships of containment policies and travel outcomes, and underscore the importance of a coordinated strategy to mitigate some of t...
Walking for transportation is a common and accessible means of achieving recommended physical act... more Walking for transportation is a common and accessible means of achieving recommended physical activity levels, while providing important social and environmental co-benefits. Even though walking in rapidly growing urban areas has become especially challenging given the increasing dependence on motorised transportation, walking remains a major mode of transportation in Latin American cities. In this paper we aimed to quantify selfreported walking for transportation in Mexico City, Bogota, Santiago de Chile, Sao Paulo, and Buenos Aires, by identifying both walking trips that are conducted entirely on foot and walking events involved in trips mainly conducted on other means of transportation (e.g. private vehicle, public transit) among individuals ≥5-years old. We show how walking-only trips account for approximately 30% trips in the analysed cities, and we evidence how the pedestrian dimension of mobility is largely underestimated if walking that is incidental to other transportation modes is not accounted for: when considering all walking events, we observed an increase between 73% and 217% in daily walking time. As a result, we estimated that between 19% and 25% of residents in these cities meet the WHO physical activity guidelines solely from walking for transportation. The results of the study also suggest that the promotion of public transportation in large Latin American cities can especially help certain population groups achieve the daily recommended levels of physical activity, while among low-income groups accessibility and safety seem to be the key challenges to be addressed.
Tel (919) 962-4760, Fax (919) 962-5206, Email: khattak@email.unc.edu Web: http://www.planning .un... more Tel (919) 962-4760, Fax (919) 962-5206, Email: khattak@email.unc.edu Web: http://www.planning .unc.edu/facstaff/faculty/khattak.htm ... Robert J. Schneider Sprinkle Consulting, Inc. 535 Main St., Suite 211 Laurel, MD 20707 ... Felipe Targa Carolina Transportation Program ...
... impact. Indeed, Cate and Richards (5) found that rollover crashes in Tennessee were most comm... more ... impact. Indeed, Cate and Richards (5) found that rollover crashes in Tennessee were most common in the overnight hours (suggesting that these crashes may be related to driver fatigue and diminished sight distances). Improving ...
Several studies of transportation and economic development impacts have recognized the extent to ... more Several studies of transportation and economic development impacts have recognized the extent to which changes in accessibility triggered by transportation improvements may translate into business cost savings and contribute to a region's economic competitiveness. This paper specifies and empirically tests a general model that captures the intensity of business activity (at the zip code level) as a function of local and regional accessibility, agglomeration economies, and region-specific effects. The geographic area of analysis is a four-county region in Maryland. The econometric analysis establishes a significant association between transportation supply and business activity in the study area. The findings suggest a clear positive association between access to primary highway facilities and the level of economic activity. The results also confirm expectations that roads with higher functional form and capacity are likely to be spatially associated with a higher intensity of economic activity. The models described in the paper provide the basis for examining regional economic effects related to new transportation facilities.
Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the t... more Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the transport implications of these policies have been overlooked. This paper examines the impact that containment policies have on population density and vehicle miles travelled per capita. An empirical analysis is conducted, relying on a fixed-effects model for panel data for the largest 25 metropolitan areas in the US during the 1982-94 time-period. Because the outcomes are endogenously related, instrumental variable regression is used to test hypotheses about the effect of the presence and age of containment policies on travel. The findings suggest that local containment policies and state-level involvement in enabling or mandating growth management are associated with higher population density and more miles travelled. The results uncover unanticipated relationships of containment policies and travel outcomes, and underscore the importance of a co-ordinated strategy to mitigate some of the potential travel consequences of containment policies.
PAY INCENTIVES AND TRUCK DRIVER SAFETY: A CASE STUDY DANIEL A. RODRÍGUEZ, FELIPE TARGA, and MICHA... more PAY INCENTIVES AND TRUCK DRIVER SAFETY: A CASE STUDY DANIEL A. RODRÍGUEZ, FELIPE TARGA, and MICHAEL H. BELZER* This paper explores the safety consequences of increasing truck driver pay. The test case the authors examine involves a large ...
-Society pays a cost for truck crashes in terms of operational disruptions, injuries and loss of ... more -Society pays a cost for truck crashes in terms of operational disruptions, injuries and loss of life. Among the 700 large-truck occupant fatalities that occur every year, about 400 occur in single-vehicle truck crashes and many involve rollovers. This study attempts to understand how truck driver behaviors, vehicle factors and crash events influence large-truck rollovers and occupant injuries in single-vehicle crashes. A relatively clean crash and inventory database, named HSIS (Highway Safety Information System) is used for crash analysis. The data come from police-reported crashes in North Carolina for 1996-1998. Over this three-year period, truck rollovers occurred in almost 30% of the 5,163 single-vehicle truck crashes. Rollover propensity is investigated using binary probit models, and injury severity is examined using ordered probit models. Injury severity is measured on the KABCO scale from fatal, severe, moderate, minor to no injury. New insights that emerge about the direct and indirect effects of high-risk factors imply that through a combination of countermeasure strategies, we must attempt to: 1) Reduce dangerous truck-driver behaviors, particularly speeding, reckless driving, alcohol and drug use, non-use of restraints, and traffic control violations. 2) Reduce truck exposure to roadways that have dangerous geometry, particularly more curves. 3) Explicitly deal with the transportation of hazardous materials and with reducing post-crash fires.
The contents of this report reflect the views of the authors who are responsible for the facts an... more The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation.
This paper explores the safety consequences of increasing truck driver pay. The test case the aut... more This paper explores the safety consequences of increasing truck driver pay. The test case the authors examine involves a large over-the-road truckload firm that on February 25, 1997, raised wages an average of 39.1%. An analysis that controls for demographic and operational factors, including prior driving experience and experience acquired on the job, suggests that for drivers employed during the lower pay regime and retained in the higher pay regime, crash incidence fell. A higher pay rate also led to lower separation probability, but this indirect effect only translated into fewer crashes by increasing the retention of older, more experienced drivers. These findings suggest that human capital characteristics are important predictors of driver safety, but that motivational and incentive factors also are influential. *Daniel A. Rodríguez is Assistant Professor of City
This report develops a comprehensive understanding of the truck-safety problem from the perspecti... more This report develops a comprehensive understanding of the truck-safety problem from the perspective of: 1) Roadway hazards, involving analysis of truck-involved crashes in work zones; 2) Socio-economic and driver occupational factors, involving examination of driver and work characteristics on truck crash occurrence and frequency. More specifically, the study is split into two parallel but complementary efforts, one relying on Highway Safety Information System crash and road inventory data and another looking at a longitudinal dataset of crashes, truck-driver characteristics and occupational factors obtained from a major for-hire truck-carrier. Two manuscripts resulting from each parallel research effort are included in the body of the report. The first effort analyzes how work zone attributes (such as type of work zone, presence of warning signs and cones, type of activity in the work zone, location of the crash in the work zone, construction impact of the wok zone on the roadway a...
The contents of this report reflect the views of the authors who are responsible for the facts an... more The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation. Report for MOU 363
These results translate into an elasticity of-0.31 for local accessibility and 0.44 for proximity... more These results translate into an elasticity of-0.31 for local accessibility and 0.44 for proximity-related effects. Based on a comprehensive literature review, this is the first empirical study in recent decades that consistently estimates evidence regarding the nature and magnitude of accessibility and proximity-related impacts of BRTs. Such evidence has a wide range of practical applications, from determining the usefulness of innovative land-based tax instruments that hinge on the capitalization of positive busway effects, to informing policy-makers about the land development consequences of transportation infrastructure alternatives.
Advanced Traveler Information Systems are becoming an integral part of urban transportation syste... more Advanced Traveler Information Systems are becoming an integral part of urban transportation systems. This paper discusses issues related to how people access, acquire and use travel information. The perceived benefits and willingness to pay for dynamic information are discussed. Empirical evidence from a major field operational test is examined to answer questions about why, how and who uses travel information. Empirical evidence suggests that information helps travelers to switch routes and departure time. The potential for information benefits is perhaps higher in cases of unexpected incidents. However, only one-third of the Target survey respondents changed their travel decisions in response to the incident. While this is a significant number in terms of demand reduction due to information, perhaps the full benefits of dynamic information are not realized because the quality of information available in just such situations is relatively low. New information media can focus on var...
Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the t... more Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the transport implications of these policies have been overlooked. This paper examines the impact that containment policies have on population density and vehicle miles travelled per capita. An empirical analysis is conducted, relying on a fixed-effects model for panel data for the largest 25 metropolitan areas in the US during the 1982 –94 time-period. Because the outcomes are endogenously related, instrumental variable regression is used to test hypotheses about the effect of the presence and age of containment policies on travel. The findings suggest that local containment policies and state-level involvement in enabling or mandating growth management are associated with higher population density and more miles travelled. The results uncover unanticipated relationships of containment policies and travel outcomes, and underscore the importance of a coordinated strategy to mitigate some of t...
Walking for transportation is a common and accessible means of achieving recommended physical act... more Walking for transportation is a common and accessible means of achieving recommended physical activity levels, while providing important social and environmental co-benefits. Even though walking in rapidly growing urban areas has become especially challenging given the increasing dependence on motorised transportation, walking remains a major mode of transportation in Latin American cities. In this paper we aimed to quantify selfreported walking for transportation in Mexico City, Bogota, Santiago de Chile, Sao Paulo, and Buenos Aires, by identifying both walking trips that are conducted entirely on foot and walking events involved in trips mainly conducted on other means of transportation (e.g. private vehicle, public transit) among individuals ≥5-years old. We show how walking-only trips account for approximately 30% trips in the analysed cities, and we evidence how the pedestrian dimension of mobility is largely underestimated if walking that is incidental to other transportation modes is not accounted for: when considering all walking events, we observed an increase between 73% and 217% in daily walking time. As a result, we estimated that between 19% and 25% of residents in these cities meet the WHO physical activity guidelines solely from walking for transportation. The results of the study also suggest that the promotion of public transportation in large Latin American cities can especially help certain population groups achieve the daily recommended levels of physical activity, while among low-income groups accessibility and safety seem to be the key challenges to be addressed.
Tel (919) 962-4760, Fax (919) 962-5206, Email: khattak@email.unc.edu Web: http://www.planning .un... more Tel (919) 962-4760, Fax (919) 962-5206, Email: khattak@email.unc.edu Web: http://www.planning .unc.edu/facstaff/faculty/khattak.htm ... Robert J. Schneider Sprinkle Consulting, Inc. 535 Main St., Suite 211 Laurel, MD 20707 ... Felipe Targa Carolina Transportation Program ...
... impact. Indeed, Cate and Richards (5) found that rollover crashes in Tennessee were most comm... more ... impact. Indeed, Cate and Richards (5) found that rollover crashes in Tennessee were most common in the overnight hours (suggesting that these crashes may be related to driver fatigue and diminished sight distances). Improving ...
Several studies of transportation and economic development impacts have recognized the extent to ... more Several studies of transportation and economic development impacts have recognized the extent to which changes in accessibility triggered by transportation improvements may translate into business cost savings and contribute to a region's economic competitiveness. This paper specifies and empirically tests a general model that captures the intensity of business activity (at the zip code level) as a function of local and regional accessibility, agglomeration economies, and region-specific effects. The geographic area of analysis is a four-county region in Maryland. The econometric analysis establishes a significant association between transportation supply and business activity in the study area. The findings suggest a clear positive association between access to primary highway facilities and the level of economic activity. The results also confirm expectations that roads with higher functional form and capacity are likely to be spatially associated with a higher intensity of economic activity. The models described in the paper provide the basis for examining regional economic effects related to new transportation facilities.
Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the t... more Despite earlier attempts to evaluate the consequences of urban containment policy adoption, the transport implications of these policies have been overlooked. This paper examines the impact that containment policies have on population density and vehicle miles travelled per capita. An empirical analysis is conducted, relying on a fixed-effects model for panel data for the largest 25 metropolitan areas in the US during the 1982-94 time-period. Because the outcomes are endogenously related, instrumental variable regression is used to test hypotheses about the effect of the presence and age of containment policies on travel. The findings suggest that local containment policies and state-level involvement in enabling or mandating growth management are associated with higher population density and more miles travelled. The results uncover unanticipated relationships of containment policies and travel outcomes, and underscore the importance of a co-ordinated strategy to mitigate some of the potential travel consequences of containment policies.
PAY INCENTIVES AND TRUCK DRIVER SAFETY: A CASE STUDY DANIEL A. RODRÍGUEZ, FELIPE TARGA, and MICHA... more PAY INCENTIVES AND TRUCK DRIVER SAFETY: A CASE STUDY DANIEL A. RODRÍGUEZ, FELIPE TARGA, and MICHAEL H. BELZER* This paper explores the safety consequences of increasing truck driver pay. The test case the authors examine involves a large ...
-Society pays a cost for truck crashes in terms of operational disruptions, injuries and loss of ... more -Society pays a cost for truck crashes in terms of operational disruptions, injuries and loss of life. Among the 700 large-truck occupant fatalities that occur every year, about 400 occur in single-vehicle truck crashes and many involve rollovers. This study attempts to understand how truck driver behaviors, vehicle factors and crash events influence large-truck rollovers and occupant injuries in single-vehicle crashes. A relatively clean crash and inventory database, named HSIS (Highway Safety Information System) is used for crash analysis. The data come from police-reported crashes in North Carolina for 1996-1998. Over this three-year period, truck rollovers occurred in almost 30% of the 5,163 single-vehicle truck crashes. Rollover propensity is investigated using binary probit models, and injury severity is examined using ordered probit models. Injury severity is measured on the KABCO scale from fatal, severe, moderate, minor to no injury. New insights that emerge about the direct and indirect effects of high-risk factors imply that through a combination of countermeasure strategies, we must attempt to: 1) Reduce dangerous truck-driver behaviors, particularly speeding, reckless driving, alcohol and drug use, non-use of restraints, and traffic control violations. 2) Reduce truck exposure to roadways that have dangerous geometry, particularly more curves. 3) Explicitly deal with the transportation of hazardous materials and with reducing post-crash fires.
The contents of this report reflect the views of the authors who are responsible for the facts an... more The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California. This report does not constitute a standard, specification, or regulation.
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