Survey of Residency Training in Preoperative.39[1] | Anesthesiologist | Residency (Medicine)

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  Objective of the Test: The objective of the test is to estimate traffic volume and travel time using moving vehicle method. Scope of the Test:    The travel time study provides data on the amount of time it takes to traverse a specified section of roadway. Such studies also provide speed and, usually, delay data.    Travel time and delay characteristics are good indicators of the level of service is being  provided, and can be used as a relative measure of efficiency of flow.    Sufficiency ratings, congestion indices, or quality indices are all methods used to compare different road-ways, and they are often based on travel time.    Before-and-after studies utilize data on travel time and delay to determine the effectiveness of a change in parking restrictions or signal timing, new one-way streets, and similar changes.    Assignment of traffic to networks and to new or improved facilities is based upon relative travel time, in addition to other factors. This has a marked bearing on the  physical plan and design of new facilities and on the nature of improvements to existing facilities.    Economic studies, such as benefit-cost analyses, use travel time data to evaluate the  benefits of time saving.    Trend studies use travel time data to evaluate the level of service as it changes with the  passage of time. Assumptions of the Method Itself:    A test vehicle makes a series of test runs in each direction over the route under study. For reliable results, a minimum of six test runs should be made in each direction under comparable conditions.    The method is applicable to two-way routes only. It has been found to be economical and to produce satisfactory, unbiased estimates of volume and travel time.     The test route is divided into sections which are as uniform as possible with respect to  physical conditions (width, number of lanes, parking, etc.) and traffic conditions (volume, speed, type of traffic, etc.).    As the test car cannot turn instantaneously, there is a time loss while the vehicle turns, which may allow some error to occur.    Also, one run may not be statistically representative of average conditions. For these reasons, the method is considered an estimate, and several runs are made and the results averaged. Assumptions Made While Executing the Method:    The test route was not uniform with respect to physical conditions (width, number of lanes, parking, etc.) and traffic conditions (volume, speed, type of traffic, etc.) but it was considered to be a straight & uniform section.      The test route had several intersections but it was assumed that there was no intersections in the test route.      Due to time constraints 4 (four) runs were made for few tests.  Related Formulas: Figure: Moving vehicle method Hourly volume for one directional flow on the section, under existing conditions, is determined  by the following formula:     = 60(        )       Where, V w = volume per hour, westbound (for eastbound volume all subscripts are reversed) M e = opposing traffic count of vehicles met when the test car was traveling east O w = number of vehicles overtaking the test car while traveling west P w = number of vehicles passed by the test car while traveling west T w = travel time when traveling west, in minutes T e = travel time when traveling east, in minutes The average travel time for one directional flow is determined by the following formula:    =     60(     )   Where,    = average travel time of all traffic westbound (for eastbound travel time subscripts are reversed) The space mean speed for one directional flow is determined by the following formula:    = 60   Where, S w = space mean speed westbound, in miles per hour d = length of test section, in miles  Sample Calculation:    = 60(        )       = ∗(2.433+2.−.)3.2+3.333   = 1890.87 vehicles/hour    =     60(     )   = 3.26 - ∗(2.−.).  = 5.76 min    = 60   = ∗.355.  = 7.11 miles/hour  K  w =         = 1890.877.11  = 265.6 vehicles/mile Results: For Westbound Trips (Polashi to Doel Chattor) Length of Test Section, d (miles) = 0.683508312 Hourly Volume, V w (vehicles/hours)   = 1890.871432 Average Travel Time, T  ̅ w  (min) = 5.760434413 Space Mean Speed, S w  (miles/hour) = 7.119341311 Density, K  w  (vehicles/mile) = 265.5964013
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