bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining the Best Method for Measuring No-Passing Zones
Authors: Brown Richard L. , Hummer Joseph E.
Published: April 2007

The objective of this study was to develop and test a suitable method for measuring passing sight distance on two-lane, two-way highways by using one person and vehicle. A literature review and contacts with state department of transportation (DOT) engineers revealed a number of current methods, and the research team developed several new methods. However, many of the current and new methods had problems that precluded agencies from using them. Five promising methods remained for an experiment testing their accuracy relative to the slow but trust-worthy walking method: the two-vehicle method, which is the most popular method used by state DOTs, a one-vehicle method used in a few divisions of the North Carolina DOT, a new laser rangefinder method, a new optical rangefinder method, and a new speed and distance method. The experiment provided data at 20 horizontal curve sites and 20 hill sites, equally split between the piedmont and mountain regions of North Carolina. The researchers recorded the time required to perform each method and also considered equipment costs, conservatism, and training needs. On the basis of these factors, the researchers recommend that highway agencies use the one-vehicle method to measure passing sight distance in most cases. The one-vehicle method was generally more accurate than the two-vehicle method, and it was superior to the new methods in several important ways.
Design Speed and Operating Speed in Rural Highway Alignment Design
Authors: Krammes Raymond A.
Published: April 2007

The relationship between design speeds and operating speeds on twolane rural highway alignments is evaluated. The current policy on design speed and its origins is described, and empirical evidence of disparities between design speeds and operating speeds are presented. U.S. policy on selecting and applying design speeds is critiqued, modifications to the design-speed concept in Australia and Europe are discussed, and possible revisions to U.S. policy on design speed are identified.
Speed Reduction as a Surrogate for Accident Experience at Horizontal Curves on Rural Two-Lane Highways
Authors: Anderson Ingrid B. , Krammes Raymond A.
Published: April 2007

A proposed speed profile model was used to estimate the reduction in 85th percentile speeds from the approach tangent to the midpoint of 1,126 horizontal curve sites on rural two-lane highways in three states. The sites were divided into eight speed-reduction intervals, the mean accident rate and mean speed reduction were computed for each category, and linear regression was performed to analyze the statistical relationship between mean accident rate and mean speed reduction. Similar analyses were performed with degree-of-curvature intervals to compare mean degree of curvature and mean speed reduction as predictors of accident experience. The results suggest that estimated speed reduction is a useful measure that helps explain how accident experience at horizontal curves on rural two-lane highways varies with degree of curvature. Horizontal curves that require speed reductions [generally, curves sharper than about 4°, a condition that corresponds with design speeds less than 100 km/h (60 mph) and estimated 85th percentile speeds less than drivers’ desired speeds on long tangents] have higher accident rates than curves that do not require speed reductions. When curve sites are grouped into speed-reduction intervals, there is a statistically significant relationship between the intervals’ mean accident rate and mean speed reduction. The mean accident rate increases approximately linearly with the mean speed reduction.
Geometric Design of Low-Speed Urban Streets
Authors: Tarris Joseph P. , Mason John M. , Antonucci Nicholas D.
Published: April 2007

A research effort is progressing to develop a rational process for designing roadway geometric elements on low-speed urban streets and using a “target”operating speed as the preselected design speed. The goal is to provide geometric street designs that reflect the in situ operating environment (form to follow function). Such an approach produces geometric conditions that result in operating speeds that are consistent with driver expectations and commensurate with the function and purpose of the roadway. The data collection methodology being used to develop a speed-prediction model between operating speed and roadway geometry, roadside features, land use, and traffic engineering considerations is also described. A comparison of design speed and operating speed for one study site is provided as an example of anticipated results.
Truck Speed Profiles
Authors: Bester Christo J.
Published: April 2007

The speed profiles of trucks in rolling and mountainous terrain are important when assessing design consistency of highways. A method is described for calculating speed profiles for trucks on a vertical alignment. It proceeds from the assumption that acceleration of a truck is a linear function of its speed. The main advantage of the method is that a speed profile can be calibrated for a specific population of trucks. A few examples are given.
Transportation Market Reforms for Sustainability
Authors: Litman Todd
Published: April 2007

The potential of using market-based reforms to address economic, social, and environmental problems associated with transportation is explored. Various transport-market distortions are identified and discussed, and strategies to reduce the distortions are described. Several technically feasible strategies are identified that increase consumer choice and encourage more efficient use of transportation resources. These are called “win-win transportation solutions.” Three packages of state-level market reforms are evaluated for their impacts on vehicle travel, emissions, congestion, consumer expenses, tax revenue, and equity. The proposed reforms represent “no regrets” actions that are cost-effective and justified for their direct economic benefits while also achieving social and environmental objectives. This approach is particularly important for sustainable transportation. Win-win solutions are predicted to meet Kyoto emission-reduction targets, increase economic productivity and competitiveness, provide net benefits to consumers, and increase overall equity, while helping solve common transportation problems such as traffic congestion and facility costs.
Role of the Motor-Vehicle Industry in a Sustainable Transportation System
Authors: Richardson Barbara C.
Published: April 2007

A sustainable transportation system is one in which fuel consumption, vehicle emissions, safety, congestion, and access to social and economic opportunity are of such levels that they can be sustained into the indefinite future without compromising the ability of future generations to meet their own transportation needs. Each of the stakeholders in the transportation system—local, state, and federal governments; the fuel and motor-vehicle industries; and public-transportation providers, users, and others—will have roles to play in moving toward sustainability. The motor-vehicle industry, as manufacturers of the vehicles that are used for 99 percent of the personal ground veh-km of travel, will need to participate proactively with all of the stakeholders in the transportation system as it addresses the challenges and opportunities in the areas of fuel consumption, emissions, congestion, safety, and access.
Evaluating Carsharing Benefits
Authors: Litman Todd
Published: April 2007

Carsharing is an automobile-rental service intended as a substitute for private-vehicle ownership. Carsharing emphasizes affordability and convenience. Vehicles are located near residences, rented by the hour, and require minimal effort to check in and check out. Carsharing services are common in some European countries and are increasingly common in North America. Carsharing gives consumers a practical alternative to owning a personal vehicle that is driven fewer than 10 000 km (6,000 mi)/year. Carsharing has lower fixed costs and higher variable costs than private-vehicle ownership. This price structure makes occasional use of a vehicle affordable, even to low-income households. It also gives drivers an incentive to minimize their vehicle use and to rely on other travel options as much as possible. Carsharing typically reduces average vehicle use by 40 to 60 percent among drivers who rely on it, making it an important transportation demand-management strategy. Despite these benefits, the use of carsharing is growing slowly and will need to overcome several barriers to achieve its full potential.
Design of a Randomized Tining Rake for Portland Cement Concrete Pavements Using Spectral Analysis
Authors: Saad Ziad S. , Jaeckel John R. , Becker Yosef Z. , Kuemmel David A. , Satanovsky Alex , Ropella Kristina
Published: April 2007

Uniformly spaced, transverse-tined portland cement concrete (PCC) pavements have been in extensive use in the United States since the early 1970s. However, driving on tined pavements generates an uncomfortable acoustic “whine”that has a discrete frequency. Recent research by the Wisconsin Department of Transportation (WisDOT) and FHWA led to an interim guideline for randomization of the tining pattern. The guideline called for tine spacing varying from 10 to 40 mm, with 50 percent of the spacing below 25 mm. At least five states have experimented with this random pattern, with limited success in eliminating the whine. A study was completed recently as part of a WisDOT contract with Marquette University and the HNTB Corporation, and funded by FHWA, to analyze all of the pavements. The tonal properties of acoustical noise were related to the serial arrangement of the tining, showing that the frequencies can be predicted from the power spectrum of the series of tines. A method of designing the series of tines that minimizes and possibly eliminates the presence of these whines is proposed and explained. By predicting the tonal properties of acoustical noise at the rake-design stage, the construction effort in building and researching noise and texture characteristics is substantially reduced. A random rake, designed using the proposed methodology, has been used in tining a road section, and preliminary spectral analysis of the acoustic noise revealed no tining-related discrete tones.
Assessing Public Benefits of Reusing Waste Materials in Highway Projects: A Framework and Decision-Support Tool
Authors: Hyman William A. , Johnson Bruce L.
Published: April 2007

The State of Minnesota frequently receives requests from outside sources regarding the acceptance of waste materials for reuse in highway construction and maintenance projects. These waste materials can include glass, roofing shingle tabs, shredded tires, coal ash, railroad ties, and taconite tailings. The Minnesota Department of Transportation (MnDOT) recently established a policy requiring the use of such materials if they have both short- and long-term public benefits. MnDOT sought a framework to assess these benefits. A decision framework and decision-support tool—in the form of an electronic spreadsheet—were developed, tested, and refined through the application of three case studies. The framework and the spreadsheet decision-support tool are described, and results are presented from one of the case studies. This information illustrates the types of input the spreadsheet requires and the output it produces. The spreadsheet is a flexible tool that accounts for a variety of materials and their placement in highways. It compares ( a) the discounted present value over a 20-year period of incremental increases in highway construction and maintenance costs as a result of using broken glass in roads with ( b) the avoidable costs of disposal by transporting the waste and landfilling it or disposing of it at the source—that is, where the waste material is generated.
Social Costs of Aircraft Noise and Engine Emissions: Case Study of Amsterdam’s Schiphol Airport
Authors: Morrel Peter , Lu Cherie H.-Y.
Published: April 2007

With the increasing trend of charging for externalities and the aim of encouraging the sustainable development of the air transport industry, there is a need to evaluate the real social costs of the undesirable side effects of aircraft noise and engine emissions. The mathematical models, based on extensive literature reviews of existing externality measurements, are developed to derive the social costs of noise and engine emissions from aircraft movements in monetary terms by using Amsterdam’s Schiphol Airport as a case study. Furthermore, the results of a survey on the current noise and engine emissions charges are briefly described and compared. The hedonic price method is applied to calculate the annual social cost of aircraft noise during the landing and takeoff stages of the flight. In contrast, the direct evaluation method is applied to estimate the social cost of each engine exhaust pollutant during different flight modes. The empirical results have shown that the average social cost of noise per aircraft landing at Amsterdam’s Schiphol Airport is similar to that of emissions, assuming a 30-min cruise time to landing or after takeoff. However, the uncertainty in the estimation of social costs for emissions is higher than that for noise, mainly because of the unknown effects of the exhaust pollutants on the upper atmosphere and on the climate.
Noise Contour Comparison of Stage 3 Hushkit Options for Boeing 727-200
Authors: Evert Meyer W. , Willkie William J.
Published: April 2007

Because of the hushkitting of older Stage 2 aircraft such as the Boeing 727 to meet Part 36 Stage 3 requirements of Federal Aviation Regulations (FARs), up to 1,000 older and noisier aircraft may still be flying in the United States after December 31, 1999. Many noise studies with FAA’s Integrated Noise Model (INM) have predicted a significant decrease in the noise contours after this date, anticipating replacement of most Stage 2 aircraft with modern Stage 3 aircraft, such as Boeing 737-700 series, Boeing 757-200, and Airbus A320 series aircraft. The INM noise footprints of a Boeing 727-200 with the Federal Express Aviation Services Inc. (FedEx) and Raisbeck Stage 3 hushkit treatments were compared with that of an unmodified Boeing 727-200 as well as that of a Boeing 757-200, which is representative of a true new-technology Stage 3 aircraft. Although the FedEx and Raisbeck Stage 3 kits are extremely cost-effective solutions for achievement of Stage 3 compliance under FAR Part 36, the real benefits to the community are somewhat limited compared with those from an aircraft designed from the outset as a Stage 3 aircraft.
Airport Automated People Mover Systems: Analysis with a Hybrid Computer Simulation Model
Authors: Lin Yi-Dar , Trani Antonio A.
Published: April 2007

Automated people movers (APMs) have become an attractive solution to mobility problems associated with large airport terminals. A hybrid computer simulation model (called APMSIM) that has been developed to simplify the operational analysis of airport APM systems is presented. Given an airport passenger demand function, along with various APM vehicle technology and airport terminal characteristics, the model estimates timevarying level-of-service characteristics of the terminal including queues and processing times. The model simulates the movement of individual passengers and APM vehicles in the system network. APMSIM constitutes a design tool for airport planners and designers for determination of the sensitivity of system performance for a range of APM design parameters, examination of the flexibility of an APM system under given operational policy and network configurations, and estimation of APM vehicle energy consumption on the basis of network constraints and system characteristics. The model is a hybrid discrete-event and continuous simulation model developed in EXTEND, a general-purpose simulation software.
Effects of Rail Stations at Airports in Europe
Authors: Widmer J.-P. , Hidber C.
Published: April 2007

The effects of rail stations, including high-speed rail, at airports in Europe are discussed in terms of a cost-benefit framework. Rail stations are operational at many European airports and are at the center of interest when road access relief at airports is considered, as well as when rail and air transport complementarity is considered. As public budget deficits are under more scrutiny than in the past and privatization of state-owned public transport companies is being considered, it is of interest to know the extent to which rail stations at airports improve the performance of the rail companies and have a positive impact on the economy as a whole (are of value to taxpayers). The study is based on a cost-benefit analysis of rail stations at five major airports (Brussels, Zurich, Frankfurt, Paris-Orly, and Paris-Charles de Gaulle) and two medium-sized airports (Geneva and Stuttgart). The results of case studies of several rail stations (those in Belgium, France, Germany, and Switzerland), which had wide spectra of technology and operating system backgrounds, showed that the overall effects of rail stations, by taking into account investment costs and the partial effects on the railways, were positive for the major (hub) airports analyzed [except in particular cases for particular reasons (Brussels and Paris-Orly)] but were balanced or negative for the medium-sized airports analyzed. The results show not only the impact of airport size but also that of distance to the airport by rail, because the benefit to users in terms of time and fare savings played a significant role and highlighted the benefits of having access to a rail network as much as possible. Finally, the effects on public transport as a whole (i.e., the effects on all public transport companies at the airport, including taxi and parking operators) were negative.
Off-Airport Passenger Check-in Facilities at Satellite Terminals: A Review
Authors: Mansel Douglas M. , Mandle Peter B.
Published: April 2007

In many regions, satellite (i.e., remote, off-airport) terminals that provide baggage check-in and baggage claim would provide several advantages to air travelers, including the ability to avoid parking at the airport or asking a relative or friend to drive to the airport, once to drop off and once to pick up the passengers; congested airline ticket counters and long lines at the skycap podiums; and traffic congestion on the way to the airport and at the airport curbsides. In some regions, such as Boston and Los Angeles, the benefits of satellite terminals have already been demonstrated, even though these terminals currently do not provide baggage check-in or baggage claim. In the United States, satellite terminals that provide baggage check-in and baggage claim serve only passengers traveling on a single airline or a distinct group of airline passengers (e.g., only passengers disembarking a cruise ship). However, baggage check-in and baggage claim for the general public is provided at several satellite terminals that serve overseas airports. The two most significant challenges to be overcome are satisfying FAA security requirements and justifying to airlines that the benefits of providing baggage check-in and baggage claim at a satellite terminal outweigh the associated costs.
Rail Transit in the Next Millennium: Some Global Perspectives
Authors: Levinson Herbert S.
Published: April 2007

Worldwide rail transit is discussed, focusing on grade-separated metro and light rail systems. Systems are compared by continent and country, number of lines per urban area, line lengths, station spacing, rail kilometers per million persons, annual rides per capita, and riders per route kilometer. Nine countries—the United States, the former Soviet Union, Germany, Japan, France, China, Brazil, the United Kingdom, and Canada—account for 68 percent of all rail transit systems. Ridership per capita is generally lowest in North America and highest on systems in the former Soviet Union. Europe has the largest number of systems, the most rail kilometers per million persons, and the third highest level in annual rides per capita. Comparisons and trends suggest a need for additional rail transit in the next millennium, as urban areas throughout the world continue to grow.
Cleveland’s Red Line Rapid: New Life for a Rail Transit Hybrid
Authors: Allen John G. , Sislak Kenneth G. , Hays Blaine S.
Published: April 2007

The Red Line of the Greater Cleveland Regional Transit Authority is a 30.3-km (19.2-mi) grade-separated, high-platform electric rail transit line running almost exclusively on railroad rights-of-way. Long assigned to the rapid transit category, the Red Line has many aspects in common, and even shares tracks, with light rail and also resembles inner-city commuter rail. Opened in 1955, the Red Line started service at a time when its urban market was entering a long period of decline. Although designed for high capacity, the Red Line has never had the opportunity to deliver on its promise. Nevertheless, the line serves an unusually wide range of metropolitan travel destinations and has the potential to develop into a regional rail line that can be a model for other cities. After years of stagnation, the Red Line is on the verge of a turnaround. The line is in the midst of a station rebuilding program and is to be extended into the suburbs beyond its west-side terminus at the airport. These developments are examined here, and other strategies are proposed that could further contribute to the Red Line’s revival.
Case Study of Potential Ground-Borne Vibration Reductions from Targeted Maintenance of Subway Cars
Authors: Zapfe Jeffrey A. , Ungar Eric C.
Published: April 2007

An extensive vibration survey was conducted on Red Line trains of the Massachusetts Bay Transportation Authority. Vibration from 420 individual train passages was recorded in the tunnel under the Beacon Hill neighborhood in Boston. A statistical model was developed to characterize the distribution of vibration levels in the fleet. Detailed vibration time histories showed that specific train cars could be identified by their vibration signature, offering a method by which maintenance could be targeted on the worst vibration offenders in the fleet. The statistical fleet model was used to predict the effectiveness of a targeted maintenance program as measured by the potential reduction in the maximum and average fleet vibration levels. A targeted maintenance program was found to reduce the maximum Red Line vibration levels by 4.5 dBV (vibration level in decibels).
Commuter Rail, Freight Railroads, and the Open Access Debate
Authors: Allen John G.
Published: April 2007

The future of the U.S. commuter rail industry is inextricably linked to that of the freight railroads. Because of recent mergers and associated operating issues, some shipper interests are seeking fundamental change in the organization of freight railroading. Under proposals for open access, railroads judged to be abusing a monopolistic position or providing inadequate service would be required to accommodate competing operators. As in the telecommunications and natural gas industries, infrastructure and service provision would be disaggregated and rail freight shippers could choose among different railroads.

Open access is expected to lead to greater volatility in freight scheduling, as bulk shippers change service providers to maximize their commercial advantage. With freight railroads already at capacity in several metropolitan areas, open access would probably exacerbate capacity problems. The possible effects on commuter operations in Washington, D.C., and Chicago are analyzed. If the United States moves toward some form of open access, commuter railroads must ensure that their operating rights are fully preserved, especially during rush hours.
Commuter Rail Service Reliability: On-Time Performance and Causes for Delays
Authors: Nelson David , O’Neil Kay
Published: April 2007

Service reliability is a key commuter rail performance indicator. All agencies calculate on-time performance statistics daily and publish periodic reports concerning trends in on-time performance. Most agencies also code their delays by cause. Information on causes and patterns of delay, however, are not widely distributed. Yet, information on the causes of unreliable service is important to commuter rail planners and operators as they seek to improve the reliability of new and existing services. The patterns and causes of delay for U.S. commuter rail systems are presented for a geographically diverse sample of six commuter rail properties, operating push-pull commuter services in seven different states. Information is provided across systems to develop general parameters for why trains are late. Variations in service reliability are reported by day of week and time of day. The reliability of short lines relative to longer services is compared. Causes for delays are evaluated, including engineering and mechanical malfunctions, programmed track work, transportation crew failures, passenger-related issues, weather, and cascades. The information is useful in determining the range of on-time performance values that might be expected of new services. It is also useful for benchmarking existing services against the general performance of a diverse set of peer services.
Replacing Parking with Transit: Evaluation of Bus Service to Offset Parking Loss During Construction of Light Rail Extension at San Diego State University
Authors: Bates Toni , Stutz Christa , Boyle Daniel
Published: April 2007

The San Diego State University (SDSU) bus service analysis study was undertaken to address two related issues—mitigation of the parking impacts of Mission Valley East (MVE) light rail transit (LRT) line construction at SDSU and the potential for “trolley emulation” service in advance of the opening of the extension. The study was undertaken to develop cost-effective bus service options to meet immediate mitigation needs and encourage travel patterns and ridership in the MVE corridor. The Metropolitan Transit Development Board estimates that 940 spaces in five campus lots will be affected by MVE construction. The recommended option is a shuttle service designed to serve the “high ridership” estimate during the peak demand hours from 8:00 a.m. to 6:30 p.m. from lots at Qualcomm Stadium to the west and Grossmont Transit Center to the east of SDSU. The availability of parking on the SDSU campus in the evening, combined with the likelihood of early morning commuters continuing to drive and park on campus in the absence of parking issues before 9:00 a.m., argues against extended hours of operation. The recommended option provides sufficient service to accommodate the estimated daily riders who would lose their parking spaces because of construction, and it could accommodate additional ridership without increased costs, especially outside of the 8:00 to 9:00 peak morning hour. In addition to the value of the study findings, the process developed to address parking mitigation needs at SDSU because of LRT construction can be applied to other service planning efforts in which demand is uncertain and no similar services exist to guide an analysis.
Effects of Enhanced Ferry Service on Golden Gate Corridor Transportation: From Dromedary to Camel: How MV Del Norte Inverted the Ferry Ridership Curve
Authors: Soumoy Pascale , Sweeny Timothy
Published: April 2007

Golden Gate Ferry commuters consider speed as the paramount issue in ferry service. Since the Golden Gate Ferry’s introduction in September 1998, ferry patrons have consistently chosen to ride the fleet’s sole high-speed catamaran, MV Del Norte, even though survey respondents have said that this ferry is less comfortable than others. The unprecedented popularity of the new service, coupled with commuter unwillingness to use ferry feeders, has resulted in the terminal’s parking lot being overburdened. This parking problem initially resulted in lower midday ridership and indirect negative effects on the system’s overall efficiency. The addition of the catamaran to its passenger ferry fleet enabled Golden Gate Ferry to increase Larkspur-to-San Francisco service from 26 to 40 weekday trips. Operating at 35 knots, this vessel reduced transbay crossing time from 45 to 30 minutes. The enhanced service attracted new riders and dramatically changed peak period ridership times, inverting the ridership curve. However, the catamaran carries 325 passengers, about one-half of the other ferries’ capacities. This limitation has resulted in unmet demand on certain commuting trips and overflow of the ferry parking facilities as passengers arrive early to board the fast boat. Golden Gate Ferry has identified two possible means of encouraging the use of ferry feeder services and decreasing the demand for the limited parking capacity: guaranteed boarding for ferry feeder patrons and enhancement of the feeder services. These first steps are crucial to smooth ferry service operations as Golden Gate Ferry prepares for the arrival of its next fast ferry in 2001.
Calibrating Pedestrian Level-of-Service Metrics with 3-D Visualization
Authors: Miller John S. , Bigelow Jeremy A. , Garber Nicholas J.
Published: April 2007

Unlike the case with airport terminals or the central business district, the quality of suburban pedestrian facilities is most likely affected less by congestion and more by safety, the walking environment, and aesthetics. Because the Highway Capacity Manual does not explicitly capture such factors when measuring pedestrian level of service (LOS), researchers have proposed innovative rating scales that do. These scales use either measurable characteristics, such as walkway width, median openings, and signalization parameters, or user perceptions, such as continuity and convenience, to rate a pedestrian facility. Unfortunately, the results of these scales are not always easy to interpret. For example, in a scaling system for pedestrian facilities in which a raised curb median counts 6 points and a blinking pedestrian-crossing signal counts 3 points, the developers of the scale believed that the median would be twice as valuable to pedestrians as the crossing signal. But would pedestrians agree? A scaling system was developed for pedestrian LOS and calibrated using visualization (computer-aided modeling techniques consisting of still shots and animations). Subjects’ perceived ratings of a pedestrian facility after they viewed still pictures and animations of the facility were compared with the computed rating of the facility from an LOS scale. The chief value of this method is that it helps ensure that pedestrian crossing needs are systematically considered and that engineers, planners, and the public agree on the calibration of a pedestrian LOS scale. The methodology is also applicable in urban areas where pedestrian needs beyond physical capacity are to be explicitly considered. The approach is original in that visualization as a simulation and data analysis tool was used to calibrate a pedestrian LOS scale.
Power of the Line: Shared-Use Path Conflict Reduction
Authors: Jordan Gihon , Leso Larry
Published: April 2007

Painting a yellow center line at blind curves on a busy multiuser path (bicyclists, pedestrians, in-line skaters, runners) decreased the percentage of people who “went the wrong way” on the path, in a before-and-after study whose sample size was 2,147. A busy 3.6-m (12-ft) paved recreational and commuting path in Philadelphia circles the Schuylkill River for 13.5 km (8.4 mi). There are numerous blind curves caused by hedges, rock outcrops, and bridge piers. Many people were traveling on the wrong side around sharp blind curves. Counts were taken and video-tapes made in order to determine the percentage of bicyclists, pedestrians, in-line skaters, and runners on the proper side, on the wrong side, and passing on the wrong side. Then a solid-yellow center line and directional arrows were neatly spray painted at the blind curves, and after counts were taken. The percentage of wrong-side travel fell from 35 percent to 15 percent, a 57 percent reduction. White lines and arrows were placed at driveways and road crossings. The white lines reduced wrongway travel from 30 percent to 10 percent, a reduction of 66 percent. Painted center lines kept people on the proper side and reduced the likelihood of conflicts and crashes. Paint is easy, fast, and inexpensive, and creates no physical obstacle; it is hard to damage and it works without education of the public.
Effects of Traffic Calming Measures on Pedestrian and Motorist Behavior
Authors: Huang Herman F. , Cynecki Michael J.
Published: April 2007

By slowing down vehicle traffic, shortening crossing distances, and enhancing motorist and pedestrian visibility, traffic calming treatments may benefit pedestrians who are crossing the street. The effects of selected traffic calming treatments on pedestrian and motorist behavior were evaluated at both intersection and midblock locations. Before and after data were collected in Cambridge, Massachusetts (bulbouts and raised intersection), Corvallis, Oregon (pedestrian refuge island), Seattle, Washington (bulbouts), and Sacramento, California (refuge islands). The key findings include that none of the treatments had a significant effect on the percentage of pedestrians for whom motorists yielded, the treatments usually did not have a significant effect on average pedestrian waiting time, and refuge islands often served to channelize pedestrians into marked crosswalks. The raised intersection in Cambridge also increased the percentage of pedestrians who crossed in the crosswalk. While traffic calming devices have the potential for improving the pedestrian environment, these devices by themselves do not guarantee that motorists will slow down or yield to pedestrians.
Sidewalk Cross-Slope Requirements of the Americans with Disabilities Act: Literature Review
Authors: Kockelman Kara , Zhao Yong , Heard Lydia , Taylor Dean , Taylor Beth
Published: April 2007

It is the long-term intent of the Americans with Disabilities Act (ADA) that publicly available services along a public street be accessible to people with disabilities via a continuous, unobstructed pedestrian circulation network. When altered, almost all streets, with the exception of rural roads and highways, will be required to provide an accessible side-walk wherever feasible. Existing research and science related to side-walk cross-slope requirements are described in detail. The history and spirit of the ADA are summarized, relevant court decisions are discussed, and key ADA cross-slope–related requirements are identified (along with applicable caveats). Current practices rely on a combination of strict, but limited, physical solutions and some programmatic solutions, about which there is much uncertainty as to how and when they should be applied. Very little existing work considers the effort and other access differences that result from changes in cross slope. Thus, additional research is needed to ensure sound policy regarding user access to transportation facilities.
New Modeling Approach for Mixed-Traffic Streams with Nonmotorized Vehicles
Authors: George Oketch Timothy
Published: April 2007

Mixed-traffic streams that contain motorized and nonmotorized vehicles are becoming more common in urban areas. These streams contain standard vehicle types such as private cars, buses, and trucks, as well as nonstandard vehicles such as bicycles, motorcycles, and other vehicular forms. Models suitable for analysis of such streams hardly exist, and most available models are limited in scope and effectiveness. Analysis of mixed streams that use traditional approaches has achieved limited success and has involved much recalibration effort and significant model modifications. Effective analysis of these streams therefore inevitably requires new models to be developed that use different approaches. Aspects of a model developed specifically for mixed streams are presented. This model covers different vehicle types, including nonmotorized ones, and allows for some special behaviors, such as seepage to fronts of queues by two-wheeled vehicles and simultaneous use of two lanes. In addition to normal car-following rules, the model incorporates lateral movement with a gradual lane change maneuver (as opposed to an instantaneous one), the decisions of which are governed by fuzzy logic rules. The model was calibrated and tested with data from Nairobi, Kenya, and its predictions were found to be in close agreement with the field data. In addition to its being a normal traffic management tool, the model makes a significant contribution to the study of the influence of nonstandard vehicle types or behavior on traffic performance.
Modeling of Bicycle Route and Destination Choice Behavior for Bicycle Road Network Plan
Authors: Hyodo Tetsuro , Suzuki Norikazu , Takahashi Katsumi
Published: April 2007

A new modeling method that describes bicycle route or destination choice behavior is presented. Although there are numerous bicycle users in Japan, the urban transportation planning process often treats bicycles and pedestrians as a single mode. Therefore, a methodology by which to evaluate and analyze bicycle demand needs to be developed. A bicycle route choice model that describes the relationship between route choice behavior and facility characteristics (e.g., road width or sidewalk) has been proposed. This model can be applied to the planning of bicycle road networks. The data from a bicycle trip survey conducted in Japan are used to study the characteristics of the model. The model is applied to study access railway station choice (destination choice). The model can produce a better fit than can a conventional model.
Analysis of Gap Patterns in Longitudinal Rumble Strips to Accommodate Bicycle Travel
Authors: Moeur Richard C.
Published: April 2007

Rumble strips can offer significant reductions in run-off-road crashes on rural highways. Newer ground-in rumble strip designs can be installed on a wider variety of shoulders, but these new designs have a much greater negative effect on bicycle traffic than did previous designs. The feasibility of placing gaps in a rumble strip pattern to permit bicycle traffic to cross the rumble strip area without striking the rumble strip pattern itself was investigated. A recommended minimum length for these gaps to accommodate bicyclists of varying abilities at speeds representative of downhill conditions was also determined. On the basis of experimental information collected, the researchers recommend that rumble strips on noncontrolled-access highways include periodic gaps of 3.7 m (12 ft) in length, and that these gaps be placed at periodic intervals at a recommended spacing of 12.2 m (40 ft) or 18.3 m (60 ft).
Evaluation of Innovative Bike-Box Application in Eugene, Oregon
Authors: Hunter William W.
Published: April 2007

An innovative “bike box”—a right-angle extension to a bike lane (BL) at the head of the intersection—was installed with accompanying traffic signs but no extra traffic signals at a busy downtown intersection featuring two one-way streets in Eugene, Oregon, in summer 1998. The box allows bicyclists traveling to the intersection in a left side BL to get to the head of the traffic queue on a red traffic signal indication and then proceed ahead of motor vehicle traffic toward a right side BL when the traffic signal changes to green. Cyclists traveling through the intersection were videotaped before and after placement of the box. The videotapes were coded to evaluate operational behaviors and conflicts with motorists, other bicyclists, and pedestrians. Twenty-two percent of the bicyclists who approached in the left side BL and then crossed to the BL on the right side of the street (the bicyclists for whom the box was most intended) used the box. Many more bicyclists in this target group could have used the box (i.e., they had a red signal indication and enough time to move into the box). A problem with motor vehicle encroachments into the box likely diminished the frequency of use. The rate of conflicts between bicycles and motor vehicles changed little in the before and after periods. No conflicts took place while the bike box was being used as intended.
Evaluation of Blue Bike-Lane Treatment in Portland, Oregon
Authors: Hunter William W. , Harkey David L. , Richard Stewart J. , Birk Mia L.
Published: April 2007

Many European cities use colored markings at bicycle–motor vehicle crossings to reduce conflicts. To determine whether such colored markings help improve safety at American bicycle–motor vehicle crossings, the city of Portland, Oregon, studied the use of blue pavement markings and a novel signage system to delineate selected conflict areas. The University of North Carolina Highway Safety Research Center (HSRC), under contract to FHWA, analyzed the project data. From 1997 to 1999, Portland marked 10 conflict areas with paint, blue thermoplastic, and an accompanying “Yield to Cyclist” sign. All of the sites had a high level of cyclist and motorist interaction, as well as a history of complaints. The crossings were all at locations where the cyclist travels straight and the motorist crosses the bicycle lane in order to exit a roadway (such as an off-ramp situation), enter a right-turn lane, or merge onto a street from a ramp. The study used videotape analysis and found most behavior changes to be positive. Significantly higher numbers of motorists yielded to cyclists and slowed or stopped before entering the blue pavement areas, and more cyclists followed the colored bike-lane path. However, the blue pavement also resulted in fewer cyclists turning their heads to scan for traffic or using hand signals, perhaps signifying an increased comfort level. The overwhelming majority of cyclists and close to a majority of motorists surveyed felt the blue areas enhanced safety. Colored pavement and signage should continue to be used and evaluated in bicycle–motor vehicle conflict areas.
Effects of Access Features and Interaction Among Driveways as Investigated by Simulation
Authors: Prassas Elena , Shenk Prassas Jin
Published: April 2007

The number, placement, and design features of driveways are important issues in access management. Simulation was used extensively so that the key parameters and variables could be controlled efficiently and so that underlying effects could be studied systematically. Some results were not surprising: deceleration lanes are important, as are acceleration lanes; the presence of driveways has some adverse effect on arterial through-vehicle speed; and the effect is greater as the number of driveways increases. But the emphasis was placed also on the effects on driveway traffic, in terms of driveway per-vehicle delay and queuing. For multiple driveways, the effect on the first (most upstream) driveway of the presence of the others was dramatic. Delay and maximum queue size increased significantly, indicating a substantial reduction in driveway capacity. This reduction was estimated at 30 to 50 percent by an analytic investigation. The effect of adding one downstream driveway was equivalent to increasing the arterial volume by 25 percent in the moderate-to-heavy flow range. Finally, the multiple driveway work revealed an oddity in that the downstream driveway performed better than it would have if it were alone. The authors attribute this to the decreased arterial environment and the “sheltering” effect of the turbulence from the upstream driveway.
How Transportation Planners and Decision Makers Address Risk and Uncertainty
Authors: Raj Mehndiratta Shomik , Brand Daniel , Parody Thomas E.
Published: April 2007

A wide cross section of transportation planners was interviewed to understand how issues related to risk and uncertainty are presently addressed in the metropolitan transportation planning process. The results and insights from these interviews are reported. It was found that many of the current responses to risks in making decisions on transportation investments could usefully be explained and improved upon by the new options approach. The examples and the analyses of the interviews show that metropolitan planning organization planners and more senior transportation executives and decision makers are certainly aware of the risks they face in investing in major transportation projects. Furthermore, they already are capable of responding to those risks in ways that can be better appreciated and explained by the options approach. What is missing in metropolitan transportation planning, and in the public-sector investment community at large, is an appreciation that there are advantages to identifying and analyzing risks early in the planning process, and that investments involving risk can be systematically analyzed in a risk management plan that uses the real-options approach. This may result in (much) higher value investments to accomplish the stated investment goals, while avoiding serious mistakes in investing in projects that may fall far short of the investment goals.
Conceptual Model to Support Systematic Use of Performance Measures in State Transportation Agencies
Authors: Baird Malcolm E. , Stammer Robert E.
Published: April 2007

State transportation agencies (STAs) have significant experience in measuring many different aspects of transportation system performance, but they have very limited experience in measuring the performance of the STA as an organization or the performance of programs for which the STA is responsible. Based on research of organizational and program performance measures, a conceptual model to help STAs develop and implement a comprehensive measurement system is proposed. The proposed model helps define the various types of performance measures and illustrates the interrelationships. Examples are offered for each type of measure. The model is flexible and can be adapted to fit unique circumstances and priorities and to focus on the aspects of performance that are most important to a particular organization. After the model and accompanying typology are explained, the utility of the model is described, with examples of beneficial uses.
Microscopic Simulation on High-Class Roads: Enhancement of Environmental Analyses and Driving Dynamics: Practical Applications
Authors: Lehmuskoski Ville , Niittymäki Jarkko , Silfverberg Björn
Published: April 2007

Traffic is a very complex phenomenon. As the calculation power and capacity of computers have rapidly increased, the possibilities for modeling traffic corresponding better to reality have also increased. A noteworthy method for modeling is microscopic simulation of traffic, which can be used for a variety of needs. In general it can be stated that the interest in microsimulation lies in short-term functional studies rather than in the assessment of long-term needs. The design of concepts for traffic management strategies, especially for main transport corridors and urban traffic systems, constitutes a challenge for the user of microscopic simulation tools. In addition to practical project planning, microscopic traffic simulation can also provide a tool for research. Detailed calculation of emissions is of special interest in congested urban areas. Microscopic simulation of traffic provides comprehensive methods for detailed assessment of emissions as each individual vehicle is recorded with respect to its driving conditions and performance both in space and in time (speed, acceleration, deceleration). HUTSIM is a Finnish microscopic simulation software developed by the Helsinki University of Technology. Because it is rule based and object oriented, the operational comprehension of the software can be expanded quite easily. In many Finnish projects, HUTSIM has been expanded to better suit wide-scale applications. Development of emission analysis and lane-change models is described, as are future development outlines concerning modeling human behavior and analyzing the level of service using fuzzy methods.