Individual versus mass transportation: feasibility of substitution

This paper is addressed to the question of social costs and social benefits (primarily environmental) which might derive from a large‐scale substitution of so‐called mass‐transit for the present, largely private, system of automotive transportation. Energy consumption and emissions are compared for the two basic alternatives and several variants. Varying degrees of physiological tolerance to pollutants are taken into account, in an attempt to develop comparable weight‐factors for different types of emissions. It is suggested that if automobiles succeed in meeting the 1975/76 emission standards set by the Clean Air Act of 1970, rail rapid transit will probably offer no advantage (in environmental terms) unless electric power is available from virtually non‐polluting sources (e.g., natural gas or nuclear plants). Economic implications of large‐scale substitution are examined, and it is noted that such substitution would involve major restructuring of our society as a whole. However, more intensive use of mass transit in central cities, possibly in conjunction with various measures to discourage the use of private automobiles in very congested areas is feasible and likely.     

The effect of railway privatization on train planning: A case study of the UK

The restructuring of the UK railway industry in preparation for privatization led to major changes being made to train planning processes. Subsequent train planning problems, some of which became very public, suggest that something went seriously wrong during the development or implementation of these revised processes. This paper investigates what went wrong and why, finding that several factors were involved, including the objectives the new processes were expected to meet and the software that was being developed to support the new processes. There are clear lessons to be learnt from the UK experience to inform debate on future railway restructuring initiatives.     

Use of third-party logistics services by large US manufacturers in 1997 and comparisons with previous years

The use of third-party logistics services by large US manufacturers continues to grow. Increasingly, those services are used to support international sourcing and sales activities. Use of these services is often triggered by specific events such as a corporate restructuring, a top management change or a benchmarking effort. Nearly two-thirds of users report they experienced significant impediments in implementing third-party agreements. After starting conservatively, the typical user buys a wide variety of logistics services. Users generally report that buying logistics services has had a positive impact on their organizations, particularly with respect to logistics costs and customer service. However, many also report negative impact on employee morale linked to downsizing the logistics workforce. More than two-thirds of users report cancelling at least one-third-party logistics contract. Nevertheless, if given complete responsibility to make the decision, >70% of users would increase their companies' use of such services.     

Evaluating Boating Safety Risk in Intracoastal Waterways

Growth in the number of recreational vessels that use inland and coastal waterways, coupled with the diversity of boating activities, results in increased boating-related conflicts, accidents, and fatalities. This situation has led to numerous requests from boaters, shorefront property owners, waterfront businesses, and local governments for the imposition and enforcement of boating safety speed zones within Florida's Intracoastal Waterways. A decision-support framework that incorporates Geographic Information Systems (GIS)–based risk assessment was developed to assist the Florida Fish and Wildlife Conservation Commission's Division of Law Enforcement evaluate requests and applications for the establishment of boating safety zones, pursuant to the Florida Administrative Code Rule 68-D-23.105 “Criteria for Approval of Regulatory Markers.” The risk assessment uses geospatial data compiled from multiple government agencies, survey data from subject matter experts, and public input from participatory workshops. Relevant spatial data includes waterway features and marine infrastructure from field surveys, vessel traffic patterns observed and mapped from aerial reconnaissance, and indicators of boater behaviors extracted from accident and citation reports. The outcome is a characterization of waterway segments according to perceived risk to boating safety. The application was tested in two Florida counties and it helped guide the establishment of new, and the revision of existing, boating regulatory zones within their Intracoastal Waterways. The application design is such that it is adaptable to waterways beyond those in Florida.     

Houston-Galveston Navigation Channel: Blueprint for the Beneficial Uses of Dredge Material

The beneficial uses of dredge material from the Houston-Galveston Navigation Channel (HGNC) to create large-scale wetlands represents a blueprint for other large U.S. ports. The port authority's interagency coordination team, the Beneficial Uses Group (BUG), successfully developed an innovative 50-year plan to deal with dredge material disposal from the channel widening and maintenance project. The creation of intertidal wetlands will initiate the restoration of the United States' second most productive estuary, in concert with the Galveston Bay National Estuary Plan, while capturing increasingly scarce government financing for port maintenance and improvement operations. An overview of the various beneficial uses of dredge material in the HGNC enlarging project is presented with a detailed investigation of the Bayport Demonstration Marsh. The HGNC project is analyzed as a prototype for successful extensive wetland creation ventures, and several key design criteria for similar large-scale marsh creation projects are given.     

Noaa's marine sanctuary program

Abstract

Authority to designate marine sanctuaries was established by Title III of the Marine Protection, Research, and Sanctuaries Act of 1972. One may view this authority as the ocean water counterpart to our National Parks and Seashores. Contained herein is a discussion of the components of the Title and how the National Oceanic and Atmospheric Administration (NOAA) plans to carry out the program. Nominations received to date are briefly discussed.     

Overcoming Governance and Institutional Barriers to Integrated Coastal Zone,Marine Protected Area,and Tourism Management in Sri Lanka

One of the major barriers to addressing complex social–ecological issues through integrated coastal management (ICM) is a lack of intergovernmental coordination and cooperation (horizontal and vertical fragmentation). This article describes an effort to overcome the barriers to ICM in Sri Lanka by fostering intergovernmental collaboration and initiating adaptive governance to restore one town, Hikkaduwa, and its associated marine protected area (MPA) and coastal zone habitats. Administrators from 12 national and local governmental agencies that are responsible for aspects of coastal management in the town of Hikkaduwa participated in a series of formal and informal workshops and a week-long tour of ICM projects in the Philippines. Outcomes demonstrate that these informal and formal meetings, workshops, and travel experiences fostered trust, social capital, and attitudinal organizational commitment (AOC). The experiences motivated members to overcome vertical and horizontal governance fragmentation through the formation of an independent intergovernmental committee for the restoration of Hikkaduwa into a sustainable and resilient community. ICM activities undertaken by the newly formed organization suggest that internal leadership capacity, effective local–national partnerships, explicitly linked ecological–economic projects, and long-term commitment are necessary conditions for success. Overall, attainment of sustainability and resilience through successful ICM should be thought of as a journey and not a destination.     

Thorium-234 derived information on particle residence times and sediment deposition in shallow waters of the south-western Baltic Sea

Activities of the naturally occurring, short-lived and highly particle-reactive radionuclide tracer ²³⁴Th in the dissolved and particulate phase were measured at three shallow-water stations (maximum water depths: 15.6, 22.7 and 30.1 m) in Mecklenburg Bay (south-western Baltic Sea) to constrain the time scales of the dynamics and the depositional fate of particulate matter. Activities of particle-associated (> 0.4 μm) and total (particulate + dissolved) ²³⁴Th were in the range of 0.08–0.11 dpm L^− 1 and 0.11–0.20 dpm L^− 1, respectively. The activity ratio of total ²³⁴Th and its long-lived and conservative parent nuclide ²³⁸U was well below unity (range: 0.09–0.19) indicating substantial radioactive disequilibria throughout the water column, very dynamic trace-metal scavenging and particle export from the water column at all three stations. For the discussion the ²³⁴Th data of this study were combined with previously published water-column ²³⁴Th and particulate-matter data from Mecklenburg Bay (Kersten et al., 1998. Applied Geochemistry 13, 339–347). The resulting average vertical distribution of total ²³⁴Th/²³⁸U disequilibria was used to estimate the depositional ²³⁴Th flux to the sediment. There was a virtually constant net downward flux of ²³⁴Th of about 28 dpm m^− 2 d^− 1 leaving each water layer of one meter thickness. Thorium-234-derived net residence times of particulate material regarding settling from a given layer in the water column were typically on the order of days, but with maximum values of up to a couple of weeks. Based on an average ratio of particulate matter (PM) to particle-associated ²³⁴Th a net flux of about 145 mg PM m^− 2 d^− 1 was estimated to leave each water layer of one meter thickness. The estimated cumulative water-column-derived particulate-matter fluxes at the seafloor are higher by a factor of about 2 than previously published sediment-derived estimates for Mecklenburg Bay. This suggests that about half of the settling particulate material is exported from the study area and/or subject to processes such as mechanical breakdown, remineralisation and dissolution. Lateral particulate-matter redistribution and particle breakdown in the water column (as opposed to the sediment) seem to be favoured by (repeated) particle resuspension from and resettling to the seafloor before ultimate sedimentary burial. The importance of net lateral redistribution of particulate material seems to increase towards the seafloor and be particularly high within the bottommost few meters of the water column.     

Determining the optimal number of seasonal adjustment factor groupings when estimating annual average daily traffic and investigating their characteristics

Although cluster analysis is recommended by the US Traffic Monitoring Guide (TMG) to supplement the development of seasonal adjustment factor groupings (SAFGs), the relationships among SAFGs' characteristics remain undiscovered, while the determination of the optimal number of clusters is an ambiguous task exposed to great subjectivity. Statistical indicators provide a mathematical solution by removing engineering judgment without taking into consideration any guidelines or other criteria, necessary for transportation planners to generate ‘practical and sensible’ groupings. The method examined in this study aims to overcome the above weaknesses incorporating into the methodology a series of statistics, recommendations, and previous research findings. The investigation of the relationships among (1) the within-group variation, (2) the total number of sites, (3) the minimum number of stations within a cluster, (4) the optimal number of clusters, and (5) the geographical size of the groups constitutes the main objectives of this research. According to the results, the cluster variability declines as the available number of stations increases. When the minimum number of stations within a cluster increases, the weighted coefficient of variation inflates as well, with the rate of increase depending on sample size. The average number of automatic traffic recorders per cluster is analogous to the sample size, while the optimal number of clusters varies conversely with the minimum number of stations within a cluster. The application developed for the conduct of the analysis minimizes the computational time needed, while it can be easily implemented by engineers to automate the process recommended by the TMG, enhancing the current state of practice.     

Trip chain complexity: a comparison among latent classes of daily mobility patterns

This paper studies the relationship between trip chain complexity and daily travel behaviour of travellers. While trip chain complexity is conventionally investigated between travel modes, our scope is the more aggregated level of a person’s activity-travel pattern. Using data from the Netherlands Mobility Panel, a latent class cluster analysis was performed to group people with similar mode choice behaviour in distinct mobility pattern classes. All trip chains were assigned to both a travel mode and the mobility pattern class of the traveller. Subsequently, differences in trip chain complexity distributions were analysed between travel modes and between mobility pattern classes. Results indicate considerable differences between travel modes, particularly between multimodal and unimodal trip chains, but also between the unimodal travel modes car, bicycle, walking and public transport trip chains. No substantial differences in trip chain complexity were found between mobility pattern classes. Independently of the included travel modes, the distributions of trip chain complexity degrees were similar across mobility pattern classes. This means that personal circumstances such as the number of working hours or household members are not systematically translated into specific mobility patterns.