Freeway Closures Research Articles

Raza Inolvidable/Unforgettable People: Artist Statement

Raza Inolvidable/Unforgettable PeopleArtist Statement Gabriel Cárdenas (bio) Between December 4, 2017 and January 12, 2018, Ventura County and parts of Santa Barbara County were set ablaze in what is known as the Thomas Fire. The fire burned through 281,893 acres, destroying 1,063 structures, and damaging 280 homes (VCFD.org). The Thomas Fire started in Santa Paula and made its way westward, blazing through Saticoy, Ventura, Ojai, and into Carpinteria. The fire burned through agricultural food lands that form the bedrock of our community’s agricultural market. This could mean drastic food shortages to our communities and those we distribute to across the nation. For example, according to the California Department of Food and Agriculture, California grows over one-third of the country’s vegetables and two-thirds of the country’s fruits and nuts (CDFA.CA.gov). Due to this emergency, many ranches, farms, and agricultural businesses depended on farmworkers to save their lands from total destruction. Latinx farmworkers had little choice but to work in the toxic and dangerous working conditions to save their employers’ commodities (Etehad 2017). This idea of choice must be understood as the relationship between farmworker and farm labor. The social skills and documentation of farmworkers is often not recognized by white American capitalism and does not allow for them to, for example, take paid days off when extreme weather events occur or have a safety net that can support them in such dire times. While fires raged, farmworkers’ blended between ash and smoke, inviting toxins into their bodies for low-waged and renewed levels of exploitation. This artist statement discusses the visual art paintings I made to reflect and critique the environmental [End Page 63] impact that wildfires have on laboring hands in agricultural havens like Ventura County, California. The Thomas Fire illustrates the precarious economic situation of farmworkers, as well as how environmental injustices are exacerbated under climate change. Many Latinx farmworkers chose to work in order to continue receiving wages and pay, whereas others who were given days off or shorter workdays were anxious of not being able to labor and generate income. Even a few days of lost wages (for some, weeks) created economic insecurities leading to loan requests from banks and/or family members. It ought to be recognized that the labor of farm-workers in our community is dependent on continuous workdays to collect income. Farmworkers have little to no options of employment due to immigration status, citizenship, and family. Moreover, additional economic strains burdened farmworkers such as food insecurity, food waste, power outages, freeway closures, loss of work/reduced workdays, school closures leading to costs for babysitters, health risks, incomplete income to pay rent/bills, and emotional and psychological stress. Their experiences illustrate environmentally related injustices due to extreme weather events within a capitalist society that favors agribusiness and profits over human life, health, and well-being. However, the exploitation of farmworkers is not new. As Laura Pulido (1996) and others have shown, the economic exploitation of farmworkers goes hand-in-hand with their exposure to environmental hazards such as pesticides, toxins, polluted air, water, and unhealthy living conditions. As a young person with parents working in the agricultural sectors of Fillmore, California, these conditions were part of everyday life. I had opportunities to work in the fields and to experience firsthand how a full day of extremely hard work would bring only a few dollars in wages. For example, hunched over for an entire day cutting peppers and assembling large metal pipes to use as sprinklers is no easy toil. Pulling weeds on your knees using a small hoe to carefully place seeds along fields amounting 300 yards and up can leave you confused and defeated. Adding to that, normal day-today high temperatures ranging in the 90s and 100s Fahrenheit, it is no wonder a young man like myself would question the capital I obtained and dread the idea of coming back the next day. My life experiences have led me to utilize my skills as an artist for social critique and social movement. Therefore, I must speak to my [End Page 64] work as an artist and how the Thomas...

Development of Breakdown Probability Models and Heavy Vehicle Passenger Car Equivalents for Rural Freeway Work Zones

With nearly nine million lane-miles of public roadway and an economy driven by the automobile, interruptions to normal traffic operations for construction and maintenance are inevitable in the U.S.A., but the substantial safety and mobility impacts associated with queueing at freeway lane closures are mitigable. The current freeway work zone capacity methodology in the 6th edition of the Highway Capacity Manual is a vast improvement over historical guidance but still approaches the issue differently than research suggests agencies and practitioners should. Namely, a capacity defined by the mean queue discharge rate is deterministic and fails to account for the stochastic nature of traffic flow and breakdown. These core issues were addressed in this research by developing a methodology for obtaining probabilistic estimates of rural freeway work zone capacity from simulated data in PTV Vissim. Results for a two-to-one lane closure were presented as a series of breakdown probability distributions to demonstrate the viability of this methodology. The data indicated that the impact of trucks on freeway capacity is exacerbated in the presence of lane closures and led to the development of work zone capacity-based passenger car equivalents. Such a procedure may be extended to freeway facilities exhibiting different geometric, traffic, and environmental characteristics and utilized by agencies to make data-driven, risk tolerance-based planning, design, and operations decisions at freeway work zones.

Assessing Public Satisfaction of Freeway Closure Measures in Fog and Haze Weather: A Questionnaire-Based Study in Hubei Province, China

In the current work, freeway closure measures in fog and haze weather are studied from the perspective of public satisfaction, in order to improve traffic management in Hubei province, China. Through an Internet survey to collect data, a structural equation model of public satisfaction of freeway closure measures in fog and haze weather is developed with public expectations, perceived quality, perceived value, public satisfaction, public complaints, support and understanding as variables. The results show that public’s supporting degree is not very high on the freeway closure measures. However, freeway intermittent release measures are the acceptable measures in fog and haze weather, which not only ensure traffic safety but also reduce economic losses and guarantee sustainable operation of freeway. Even though freeway closure measures are frequently taken due to serious fog and haze weather, intermittent release measures should also be taken into consideration so as to enhance public satisfaction and strengthen adaptive capacity of freeway to adverse weather.

Impact of temporary freeway closure on regional air quality: a lesson from Carmageddon in Los Angeles, United States.

Large cities in the United States face multiple challenges in meeting federal air quality standards. One difficulty arises from the uncertainties in evaluating traffic-related air pollution, especially the formation of secondary pollutants such as ozone and some particulate matter. Current air quality models are not well suited to evaluate the impact of a short-term traffic change on air quality. Using regional traffic and ambient air quality data from Southern California, we examine the impact of a two-day freeway closure on traffic and several criteria air pollutants (CO, NO2, O3, PM10, PM2.5). The results indicate that regional traffic decreased about 14% on average during the closure. Daily average PM2.5 levels decreased by about 32%, and daily 8 h maximum ozone levels decreased by about 16%. However, the daily 1 h maximum NO2 concentration was higher at some sites during the closure. Despite the mixed results with NO2, this study provides empirical evidence to support traffic reduction as an effective strategy to address chronic air pollution problems, especially with regard to ozone, in Southern California.

Evaluation of Dynamic Message Signs on Rural Freeways: Case Study of a Full Freeway Closure

The evaluation of dynamic message signs (DMSs) has been challenging to undertake because of the difficulty of identifying the effects of DMSs from traffic patterns. The primary contribution of this study is the comprehensive evaluation of DMSs in a rural area during a full freeway closure by using field data, driver surveys, and simulation. A full freeway closure scenario offers an opportunity to identify the effects of DMSs, because there is a network-wide shift in traffic demand from the closed route to the alternate route(s). A unique data collection and analysis approach was used to capture regional traffic patterns, including the processing of all traffic movements from four full interchanges. A significant increase in traffic flow on the detour route and a corresponding decrease on the affected route were observed during the freeway closure. Simulation was used to isolate the benefits of DMSs from other traveler information modes such as newspaper, TV, and radio, and to explore the sensitivity of the network to different levels of driver compliance. Depending on the proportion of drivers who chose to divert based on DMSs, monetary benefits were estimated to range between US$2,394 and $65,643 for the three-day freeway closure. Driver surveys conducted during the freeway closure revealed that 57% of the drivers utilized DMS information and 41% of drivers relied solely on DMSs to obtain information related to the closure and the detour route.

Effect Analysis of Intermittent Release Measures in Heavy Fog Weather with an Improved CA Model

Heavy fog may easily cause traffic accidents; thus freeway closures are frequently taken in order to ensure traffic safety in China, which not only seriously affect the travel of people, but also bring great economic losses. This paper studies the fog related risk of rear-end collisions and the intermittent release measures taken to reduce such risk; meanwhile, an improved cellular automaton model considering driving behaviors in heavy fog is proposed. The simulation results indicate that the risk indicatorfain fog is much higher than normal weather when cellular occupancyρ<0.5. After taking intermittent release measures, the magnitude offawill drop from 10−4to 10−5under the same fog condition, which greatly enhances the safety. In addition, this paper concludes the appropriate vehicle number released for each time and the time intervalhtbetween adjacent fleets and the maximum number of vehicles𝒬maxwhich can be released per hour. These results can be used as theoretical basis and reference for the traffic management departments to develop intermittent release measures.

Commuter impacts and behavior changes during a temporary freeway closure: the ‘Fix I-5’ project in Sacramento, California

One mile of Interstate 5 (I-5) in downtown Sacramento, California was closed intermittently for reconstruction (‘the Fix project’) over nine weeks in 2008. We analyze the impacts of the Fix on commuters’ travel behavior, as measured through two contemporaneous Internet-based surveys. The impacts of the Fix on traffic conditions do not appear to have been excessive: majorities in all relevant subsamples did not find conditions worse than usual, and sizable minorities actually found them to be better. Among the active changes to commute trips, the easiest options – avoiding rush hour and changing route – were the most common (adopted by 48% and 44%, respectively). Among the changes that reduced vehicle-miles traveled, increasing transit use and increasing telecommuting (TC) were the most common (each adopted by 5–6% of the relevant subsample). Binary logit models of these two choices suggest that persuading current adopters to increase their frequency of use is easier than convincing nonadopters to start TC or switch to transit. Women and those in larger households were found to be more likely to increase TC and transit use. Employer support of commute alternatives significantly influenced the adoption of both strategies.

Calculation of Changes in Drive-Alone Commute, Vehicle Miles Traveled, during Temporary Freeway Closure

A 1-mi stretch of Interstate 5 in downtown Sacramento, California, was closed intermittently for reconstruction (i.e., “the Fix”) in the summer of 2008. With data collected from two contemporaneous surveys of affected workers, the study reported in this paper estimated changes in drive-alone commute, vehicle miles traveled (DACVMT) as a result of Fix-related mode shifts, switches to (increased) telecommuting (TC) and compressed work week (CWW) schedules, personal leave (PL) days, and departures from the region (DFR) (i.e., out of town for the entire study week). Distinctions were made for the first three causes for the changes, which were characterized as possibly permanent, and the latter two, which were definitely temporary. Net DACVMT changes were distinguished further by respondents who made overall positive changes and overall negative changes. During the target week, the total Fix-related VMT reduction for the entire affected sample (N = 6,185) was estimated to be between 5.36% and 5.48%. Reductions from potentially permanent sources led to an estimated 4.08% to 4.21% reduction, and those from definitely temporary sources led to a 1.27% reduction. Mode shifts reduced DACVMT between 3.04% and 3.17% (the net of a 0.42% increase by 32 respondents and a 3.46% to 3.59% decrease by 257 respondents; seven respondents made drive alone–related mode shifts that resulted in no net DACVMT change). Increased TC and CWW engagement contributed additional 0.71% and 0.33% reductions, respectively. PL time and DFR reduced DACVMT by 0.15% and 1.12%, respectively.

Nonwork Travel Behavior Changes during Temporary Freeway Closure

A 1-mi stretch of Interstate 5 in downtown Sacramento, California, was intermittently closed for reconstruction in the summer of 2008. Nonwork travel behavior changes during the reconstruction were investigated with the use of data from two contemporaneous Internet surveys. More than half of the sample of 6,362 respondents made at least one studied change during the study period, including changes of route, activity location, time of day, day of an activity, and cancellation of an activity. First, the choice to make any nonwork travel change was modeled with binary probit (the any change model). Respondents were more likely to make nonwork travel changes when traffic conditions were worse than usual and less likely to do so when conditions were much better than usual. Women were more likely to make changes than men were. Those travelers who were not aware of any of the travel demand management measures designed to mitigate the impacts of the reconstruction were less likely to make nonwork changes. Next, the five individual nonwork changes were simultaneously modeled with multivariate probit. Again, women were more likely to make the individual changes studied (except route changes). The impacts of traffic conditions and commute characteristics were consistent with those in the any change model. Unobserved characteristics associated with the two temporal changes (day and time) were highly correlated, as were those associated with the two spatial changes (location and route). Unobserved influences on location, day, and time changes were highly correlated with those affecting activity cancellation.

Development of script-based travel mode choice after forced change

A previously proposed model [Transportation Research F: Traffic Psychology and Behavior 4 (2001) 89] predicts that frequent choice of a particular travel mode will result in a habitual or script-based choice of the travel mode. In Study 1 a first wave of a panel survey of 53 students at different Japanese universities was conducted 2 months before the students graduated, a second wave 3 months after graduation when the students had been employed by companies at different other locations. In many cases the change after the graduation resulted in change of respondents’ commuting mode. The results showed that script-based travel mode choice developed in those who had changed travel mode most (either to more public transport use or more automobile use). Study 2 indicated that frequent drivers who changed to public transport during a 8-day freeway closure continued to use public transport more frequently one year after the closure than did those drivers who did not change to public transport during the closure. This enduring effect was interpreted to reflect the development of a script-based travel mode choice.

Changes in Drivers’ Perceptions and Use of Public Transport during a Freeway Closure

The aim of this study was to investigate how cooperation can be facilitated in the real-world social dilemma of choosing to commute by automobile rather than by public transport. A survey of 335 drivers was carried out before and during an 8-day temporary freeway closure in Osaka, Japan. The results showed that the frequency of switching to public transport during the closure was inversely related to the frequency of automobile commuting before the closure. Furthermore, drivers who more frequently commuted by automobile overestimated commuting time by public transport to a larger extent than did drivers who commuted less frequently by automobile. At the same time, the larger the overestimation the more likely were drivers to change their perception of commute time. It is suggested that a temporary structural change, such as a freeway closure, may be an important catalyst that triggers cooperation in a social dilemma.

Cost-of-Delay Studies for Freeway Closures Caused by Northridge Earthquake

On January 17, 1994, the Northridge earthquake in California destroyed structures on four important freeways in the Los Angeles basin. Closure to travel on these damaged freeways had significant local, regional, and statewide impacts for general travel, as well as for commuter and commodities movement. Initial research indicated that the four route closures on the I-5, I-10, CA-14, and CA-118 freeways had significant ramifications on the local and state economies on the order of millions of dollars per day. With this in mind, the state of California set up high-incentive reconstruction contracts that paid private contractors significant bonuses for early reopenings of damaged routes. Further research conducted as part of the comprehensive transportation recovery evaluation justified those bonus clauses and indicated that the quantifiable (direct) transportation-related costs associated with the travel disruption and delay on the four damaged routes combined in the Los Angeles basin exceeded $1.6 million p...

Cost-of-Delay Studies for Freeway Closures Caused by Northridge Earthquake

On January 17, 1994, the Northridge earthquake in California destroyed structures on four important freeways in the Los Angeles basin. Closure to travel on these damaged freeways had significant local, regional, and statewide impacts for general travel, as well as for commuter and commodities movement. Initial research indicated that the four route closures on the I-5, I-10, CA-14, and CA-118 freeways had significant ramifications on the local and state economies on the order of millions of dollars per day. With this in mind, the state of California set up high-incentive reconstruction contracts that paid private contractors significant bonuses for early reopenings of damaged routes. Further research conducted as part of the comprehensive transportation recovery evaluation justified those bonus clauses and indicated that the quantifiable (direct) transportation-related costs associated with the travel disruption and delay on the four damaged routes combined in the Los Angeles basin exceeded $1.6 million per day. The methodology used to calculate the cost-of-delay estimates for each route was based on detailed counts, surveys, and travel time (delay) data collected during the reconstruction periods, as well as computer simulation and adopted costing techniques. The geographic and systemwide extent of the impacts of closures was simulated through travel demand assignments on EMME/2 modeled highway networks that were modified to represent the earthquake-damaged system. When the economic analysis is broadened to include indirect costs associated with trip elimination, areawide disruption to shipping, or loss of jobs caused by the earthquake emergency, a much higher transportation-related cost to the California economy can be calculated.

A simulation model of freeway lane closures

A model to simulate traffic operations at freeway lane closures is described. The model logic is based on a rational description of the behavior of the drivers in a freeway lane closure situa tion, and the program is written in SIMSCRIPT 11.5. An applica tion of the model is illustrated with evaluation of potential safety impacts of reduced speed zones in freeway lane closures at differ ent levels of assumed driver compliance.

Traffic Control at Freeway Work Sites

A comprehensive, multidisciplinary study of traffic control needs of freeway lane closures at work zones included surveys of drivers and highway patrolmen, test driver studies, field measurements of merging and speed characteristics, a digital simulation study, and the field testing of novel signs. Construction accident data, collected on a turnpike facility, was dominated by collisions with objects, many involving trucks at night in the transition area at crossovers. Rear‐end accidents resulted in higher injury rates than other accidents, most occurring in the closed lane or bidirectional area. The simulation study indicated that potential problems increase rapidly as approach volumes increase toward open‐lane capacity, but these problems can be greatly reduced if closed lane drivers can be induced to initiate early merges. Several signs designed to influence driver behavior were field tested. The results were largely inconclusive, but the “Merge Soon With Caution” sign was found to increase early merge ...