Papers by madaniyo mutabazi
Hump crossings or high-profile crossings are a highway/rail intersection at which the road surfac... more Hump crossings or high-profile crossings are a highway/rail intersection at which the road surface profile across the rail tracks may pose a risk to a low-clearance vehicle becoming stuck on the tracks. They may also pose a threat to heavy vehicles that are required to stop at the crossings due to the steep grades. States are required to identify high-profile crossings, sign them appropriately, and keep their information in an electronic database. In 1997, the Federal Highway Administration (FHWA) adopted a new advance symbol sign for crossings. However, there is no standard procedure from FHWA on how to identify such crossings. The Kansas Department of Transportation maintains an electronic database of about 7,000 public grade crossings. In 2000, they added the value of the grade to the crossing. The objective was to develop an effective process to identify and rank crossings where there may be a problem with the approach grade profiles. This identification includes some physical c...
A passing maneuver on a rural two-lane highway can be difficult and may present high risk to moto... more A passing maneuver on a rural two-lane highway can be difficult and may present high risk to motorists. Passing maneuver is also a major element influencing operational efficiency of two-lane highways. One of the most effective ways to increase passing opportunities and hence operational efficiency and safety, is to provide passing lanes. For many years, passing lanes have been provided on unsustainable grades where some vehicles experience a problem maintaining desired speed. These lanes are usually called "climbing lanes". Currently, passing lanes are becoming more common at locations other than on unsustainable grades where maintaining desired speed is not a vehicle performance characteristic problem. In this paper the term "passing lane" will refer to added lanes on sections other than unsustainable grades with an objective of increasing passing opportunities. This paper will cover: 1)an evaluation of the safety of intersections within the passing lane, 2) a ...
Transportation Research Record, 1995
Several versions of the U.S. Department of Transportation rail-highway grade crossing accident pr... more Several versions of the U.S. Department of Transportation rail-highway grade crossing accident prediction models have been developed and recommended for use in resource allocation procedures. The objective of this research was to test and evaluate the ability of these models to accurately predict future accident experience at individual grade crossings. Accident history and inventory data were assembled for 1,798 grade crossings in Wisconsin for the period from 1975 through 1989. Differences between the actual and predicted accident rates for 5- and 10-year forecast periods were evaluated using both the basic accident prediction models and the 5-year accident history adjustment to the basic model. It was found that the basic model from the first and third versions provided the best estimate of the long-run accident rate at individual grade crossings and were, therefore, recommended for use in resource allocation procedures.
Existing passing lanes in place on Kansas highways were studied from an operational and safety pe... more Existing passing lanes in place on Kansas highways were studied from an operational and safety perspective. It was found that they generally operated well, improved operational efficiency and were well liked by the public. Determination of highway segments that would need passing lane(s) to improve their operational performance should be accomplished in a two-level process; i.e., Network and Project Level. At the Network Level, two-lane rural highway segments that operate at a level-of-service below a predefined acceptable level are identified. At the Project Level, highway segments identified at the network level are ranked for the purpose of prioritization. The number of highway segment passing lane projects to be implemented will depend on the funding level. At the project level, a detailed economic analysis of different passing lane lengths, spacing, and configurations can be undertaken to set parameters with an objective of minimizing percent time delay. Computer simulation usi...
Traffic Safety on Two ContinentsPTRC Education and Research Services Limited, 2000
This paper presents a discussion of warrants for provision of passing lanes on rural two-lane hig... more This paper presents a discussion of warrants for provision of passing lanes on rural two-lane highways, and developments of passing lanes warrants for the state of Kansas. Warrants for passing lanes are considered to involve two sub tasks; namely, 1) the process of selecting highway sections which need passing lanes(s) in order to improve the quality of traffic operation; and 2) the process of selecting the physical location along the highway section to place the passing lane. Available guidelines used by different jurisdictions as reported in the literature combine the two processes directly or indirectly into one process. Combining the two processes may lead to a process which is inefficient; and may lead to providing passing lanes where they are not needed most within the state network. It is recommended that provision of passing lanes be provided at two stages. The highest stage or network level should select highway sections that are in need of improvement because of low, preva...
Transportation Research Record, 1998
Consolidation or closure of unnecessary grade crossings is a cost-effective but difficult-to-achi... more Consolidation or closure of unnecessary grade crossings is a cost-effective but difficult-to-achieve option for increasing the safety of highway-rail grade crossings. Consolidation not only needs traffic engineering expertise, it also needs the support of local government officials and citizens. It is as much a public relations effort as an engineering exercise. To win local support, proposals for closing selected crossings should appear reasonable to the public, that is, the public should be able to see a need or net benefit. A corridor study is more effective than targeting single crossings for closure. Selecting a corridor with high-potential closure candidates can be the key to the success of winning local approval. Finding the most “hazardous” crossings can help select high-potential corridors. The development of a model to pinpoint Kansas’ best candidates for closure as a key step in selecting corridors where consolidation efforts should be concentrated is described.
West Indian Medical Journal, 2007
Road traffic accidents have been increasing in Tanzania, despite some considerable efforts to red... more Road traffic accidents have been increasing in Tanzania, despite some considerable efforts to reduce the level of the problem. Road safety management is widely used worldwide in various forms and at different levels of refinement to manage traffic safety. This paper discusses and recommends the scientific methods that should be used to alleviate the road safety problems in Tanzania.
INTrODUcTION Road traffic crashes pose social and economic problems in Trinidad and Tobago (T&T) ... more INTrODUcTION Road traffic crashes pose social and economic problems in Trinidad and Tobago (T&T) and worldwide. The safety belt is a passive device that can reduce the severity of injuries to vehicle occupants during the in-crash phase. Safety belt laws point to the belief that safety belts are effective. However, such effectiveness is meaningless if safety belts are not worn. While T&T aspires to attain safety belt usage above 90 percent by the year 2030, three studies that attempted to measure safety belt usage in Trinidad indicate that the trend does not appear to be moving in that direction.1 There is a need for increased safety belt usage; however, there is no structured program of monitoring. Some car manufacturers provide laptype safety belts for rear seats. In many countries, safety belt laws are limited to front seat positions, which reflects an underestimation of the risks to rear seat passengers in the event of a car crash. Recent studies show that the use of rear seat be...
Pedestrians are the most vulnerable road users; more so in developing countries such as Trinidad ... more Pedestrians are the most vulnerable road users; more so in developing countries such as Trinidad and Tobago as drivers fail to yield right-of-way to pedestrians crossing roads. Trinidad and Tobago has introduced a new zebra crossing to increase drivers’ yielding rates. The crossing affords drivers to identify the crossing at a reasonable distance, and improve visibility of pedestrians in the crossing vicinity. This paper reports the result of a study aimed at exploring road users’ understanding of the crossing. Some crossing elements are well understood by drivers while other elements present a challenge. Drivers support the new crossing, but most pedestrians are not satisfied with drivers’ yielding rates. Through engineering, education, and enforcement improvements the crossing has a potential of improving pedestrian safety. These results will increase public education on the new crossing, and suggest crossing improvements.
This paper reports the results of a survey conducted in St. George East School District, Trinidad... more This paper reports the results of a survey conducted in St. George East School District, Trinidad on the characteristics of transport modes used by students to and from school. It also reports attitudes of students, parents and guardians on ride sharing for school trips. Most (74%) of school trips in the study area are made with motorised transport modes. Primary school students do walk to school more than secondary school students, who in turn ride shared modes (public transport and van-pooling) more than primary school students. Both primary and secondary school students ride private car mode in the similar proportion. Older students are more likely to walk to school than riding motorised transport, and they are more likely to ride shared modes more than private car. As the number of cars per household increases, share of private car mode increases at the expense of other modes. A student from a household owning a car is more likely to be driven to school than walking. The share o...
School transport and increasing motorization are considered main causes of traffic congestion in ... more School transport and increasing motorization are considered main causes of traffic congestion in Trinidad. This pilot study aimed at assessing the factors that impact school transport, school selection, and measuring attitudes towards ride sharing for school trips. Primary school students exhibit different school transport demands than secondary school students. Academic excellence is the main factor in selecting secondary schools at the expense of travel distance. School bus program is more preferable than car-pooling, and is highly approved by those using it than those using private vehicles. Living close to school and school bus’s efficiency are the main reasons for unwillingness and willingness respectively, to participate in school bus program. Addressing perceived negatives such as security, can improve attractiveness of shared modes. There is a need of policy change towards school transport in Trinidad if the country has to attain sustainable development.
Inter-island transport between Trinidad and Tobago is provided and subsidized by the republic gov... more Inter-island transport between Trinidad and Tobago is provided and subsidized by the republic government of Trinidad and Tobago. Transportation between the two islands becomes an absolute necessity because: 1) Tobago’s economy depends on tourism industry; 2) Some essential goods and services for Tobago residents can only be obtained from Trinidad; and 3) inherent social relations between residents of the two islands require physical social interactions on a daily basis. Trinidad and Tobago being separated by sizeable water body, only water transport and sea transport are feasible modes of transport between the islands. The cost of moving goods and people between the islands using water or/and air modes of transport is higher than using road and/or rail transport modes if the two islands were a single land mass. The cost is even higher when the service provided by bureaucratic inefficient government entities. When passengers don’t pay their full cost of travel they tend to make trave...
Sharp horizontal curves proceeded by long straight tangents are potential locations for vehicles ... more Sharp horizontal curves proceeded by long straight tangents are potential locations for vehicles crashes especially running-off the road. This happens when the driver enters the curve with a higher speed than the geometry and environment of the curve can support. Experience has shown that despite warning signs to the drivers on such hazardous locations still over-speeding is a major contributing factor for crashes at horizontal curves. In early 1970’s results from laboratory experiments showed that horizontal transverse marking, with decreasing spacing in the direction of travel makes drivers perceive they are traveling at higher speed (perceptual speed) than the actual speed. and hence. Field application of this concept followed afterwards with a hope that this treatment will prompt drivers to slow down. However, results from the field are inconclusive. In early 1980’s Trinidad & Tobago placed transverse markings along the southbound lanes of Solomon Hochoy highway in the vicinity of Freeport flyover. There is no evidence that these markings have ever been evaluated. The objective of this study was to evaluate the effectiveness of these markings, as they are, on reducing vehicle speeds. Analysis of traffic speeds at upstream and downstream locations of these markings does not indicate that the markings are effective in reducing vehicle speeds through driver elusion. It is suggested to conduct more speed measurements when these markings are re-painted next time before the final conclusion is reached. This study does not discourage placement of such treatment at any other location, because some studies have shown that effectiveness of these markings could be site specific.
Walking as mode of transport is receiving more attentions nowadays because of its advantages over... more Walking as mode of transport is receiving more attentions nowadays because of its advantages over motorized transport modes especially for short trips. However, pedestrians are the most vulnerable road users in developing countries, threatening walking mode. Most of pedestrian crashes in Trinidad are reported to involve a pedestrian crossing the roadway. Conventional zebra crossings are widely used to facilitate pedestrians to cross-busy roadways safely. However, most of drivers in Trinidad hardly yield to pedestrians who want to cross the road. The Government have introduced a new pedestrian zebra crossing intended to increase driver-yielding rate. Effectiveness of this new crossing to large extent depends on how drivers understand it. As part of evaluation of the new crossing, a questionnaire survey was conducted to test drivers’ understanding of some selected crossing elements. Field visit to several new zebra crossings were made to supplement information obtained from the questionnaire survey. This paper presents the results of the survey. Majority of drivers understand correctly the meanings of flashing lights and zebra markings. However, zigzag lines at the crossing were highly misunderstood by drivers. Misunderstanding of zigzag lines to some extent demonstrate the phenomenon in which highway engineers may place traffic control devices, but drivers don’t understand their meanings.
Pedestrians are the most vulnerable road user group. Most pedestrian-vehicle incidences involve a... more Pedestrians are the most vulnerable road user group. Most pedestrian-vehicle incidences involve a pedestrian crossing the roadway. The probability of a driver yielding to a pedestrian crossing a road highly depends on driver’s ability to see the pedestrian quite in advance for the driver to take appropriate evasive action. Parked and/or stopped vehicles in the vicinity of a pedestrian crossing may obstruct sights of both pedestrian and driver leading to a crash between them. To enhance pedestrian visibility at pedestrian crossings in some countries pavement zigzag line markings are used to restrict parking, stopping, and overtaking within the crossing. Like any other traffic control device, zigzag lines’ effectiveness hinges on road user’s understanding of its meaning. This paper looks back in the literature the understanding of these lines by different road user groups. The meaning of zigzag lines has proved to be a dilemma to some road users and road safety stakeholders in some countries.
Uploads
Papers by madaniyo mutabazi