Evaluating Performances of Traffic Noise Models

Traffic noise in decibel dB(A) were measured at six locations using 407780A Integrating Sound Level Meter, while spot speed and traffic volume were collected with cine-camera. The predicted sound exposure level (SEL) was evaluated using Burgess, British and FWHA model. The average noise level obtained are 77.64 dB(A), 72.95 dB(A)and 75 dB(A) respectively; B The values from Burgess and FWHA model lies within an error band of B1 5% with reference to the observed noise levels. Thus, the three models are effective in predicting equivalent traffic noise index in Akure with fair accuracy. The coefficient of correlation (R2) between observed sound exposure level and predicted sound exposure level are 0.931 and 0.968 respectively; thus, there is a good correlation between the observed and the predicted value.B Adequate road design and management of traffic flow are recommended to reduce road traffic noise in the study area.http://dx.doi.org/10.4314/njt.v33i4.

Evaluation of properties of bitumen modified with waste tyre

The research investigates the properties of bitumen modified with used tyre. Basic tests such as penetration, softening point, viscosity , flash and fire point and ductility test were carried out by using shredded waste tyre which varied from 0% to 20% by weight of 60/70 penetration grade bitumen at 1600C using dry mix method. Penetration value decreased with addition of 20% tyre while increase in softening point, viscosity, flash and fire point were obtained with the corresponding values of 80.90C 250.96 sec and 189/280.120C respectively. However, the values obtained exceeded the minimum values specified by American Standard for Testing and Materials (ASTM). The ductility value obtained with the addition of 6% and 14% tyre are 44.64cm and 40.6cm respectively. Thus, addition of 6% tyre content to bitumen is however suggested for best ductility value.Keywords: Bitumen, Waste Tyre, Penetration, Softening Point, Viscosity, Ductilit

Inter-Trip Characteristics Model for Ado-Ekiti Township, Southwest Nigeria

Travel characteristics survey and the useful time spent on road by commuters were collected from the terminals and members of National Union of Road Transport Workers. The survey also gave the travel behaviour of commuters and socio-economic characteristics over a period of time across the population. The analysis shows that a total of 7,338 Trips/per were made in Ado-Ekiti to various urban and rural area in which trip to Iworoko-Ekiti has the largest with 3,000 Trips per day. The regression analysis of travel time as dependent variable with other variables (travel cost and travel distance) gives average value of R and R2 as 93.1% and 86.6% respectively.Keywords: Travel Behaviour, Terminals, Trips, and Socio-economicCharacteristic

Accident Prediction Models for Akure – Ondo Carriageway, Ondo State Southwest Nigeria; Using Multiple Linear Regressions

Accident data on the 52km Akure-Ondo Carriageway and Spot Speed data were collected and analyzed. The analysis of the Spot Speed gives an average of 51.5km/hr and 110.75km/hr for the 15th and 85th percentile speed respectively, the 85th percentile speed is higher than the posted speed limit of 60km/hr which indicate that the vehicle travelling at this speed are susceptible to accident. The analysis for the study area also shows that 759 peopled were involved in the accidents, 108 persons were killed and about 348 persons were injured between 2002-2007, 38% of the accident were fatal accident and 62% non-fatal accident, However, the regression analysis carried out on the accident data with number of accident as the dependent variables and number of people killed in the accident(X1), number of people injure(X2), number of people involved in the accident(X3) as independent variables; gives a coefficient of correlation “R” value of 70.70% and coefficient of determination “R2”of 49.70% respectively. Factors such as driver’s behavior, poorly maintained vehicles, non adherence to traffic rules, poorly maintained road and verges, and over-speeding are causatives factors to road accident. However, road safety plans and road safety audit that are effective strategies that could be used by the authorities concerned for mitigation of road accident are recommended..Keywords: Road Accident, Carriageway, Spot Speed, Road Safety Plans and Road Safety Audi