Studies were conducted at two sits on rural roads with similar characteristics. The first site was 7.5 miles in length with an Annual Average Daily Traffic (AADT) of 7,400. Over the year-long study period, 42 crashes occurred on this portion of roadway, 5 of them resulting in fatalities. The second site was a 14-mile section with an AADT of 4,700. There were 67 crashes in this section with 5 fatalities. Determine the appropriate crash rates for both locations, and discuss the implications.

Studies were conducted at two sits on rural roads with similar characteristics. The first site was 7.5 miles in length with an Annual Average Daily Traffic (AADT) of 7,400. Over the year-long study period, 42 crashes occurred on this portion of roadway, 5 of them resulting in fatalities. The second site was a 14-mile section with an AADT of 4,700. There were 67 crashes in this section with 5 fatalities. Determine the appropriate crash rates for both locations, and discuss the implications.

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter5: Highway Safety

Section: Chapter Questions

Problem 9P

See similar textbooks

Similar questions

A state transportation agency want to evaluate engineering countermeasures applied to a two-lane,two-way rural highway segment.This 4 miles segment has been identified as having 14,19,and 23 total crashes in the last three years,before the implementation of the countermeasures.The AADT at the segment for last three years is 5630 vehicles per day and the AADT for after implementation is 6240 vehicles per day.Compute the expected average crash frequency for the after period, assuming the treatment was not implemented.The segment has the same conditions as the base conditions established for SPF.
Determine the predicted average crash frequency, in crashes (per year), on a 7-mile segment of a rural divided multilane highway with 10-ft lanes and 8-ft paved shoulders that carries an AADT of 15,000 vehicles per day. The proportion of total crashes constituted by CMF-related crashes is 0.55.
A proposed improvement will widen a two-lane rural highway from 9-ft-wide (per lane) to 11-ft-wide (per lane) if the highway has an AADT of 2100 veh/day. If there are an average of 25 crashes per year on the segment proposed for improvement, and 67% of the crashes are of the type targeted by the improvement, estimate the expected number of crashes (per year) after the improvement is constructed.
A two-lane rural roadway segment is expected to have 15 crashes (total) durch year with AADT of 1800 veh/day. The current width of the lane is 10 ft. It is prop width of the lane be increased to 12 ft. What should be expected number of crashes (total) the new condition?
A black spot funding program prioritised a project for widening a two-lane rural highway from 5.4 (=2x2.7) m to 6.6 (=2x3.3) m. This project aimed to reduce a particular set of CMF-related crash types such as single-vehicle-run-off-the-road and multiple-vehicles-head-on, opposite direction sideswipe, and the same direction sideswipes. Therefore the CMFs for lane width on the roadway segment given in Table 5.14 (Text 5.1) apply. Compute the expected average total crash frequency after the widening for the following conditions. The expected average crashes before widening = 25 total crashes/year. AADT on the highway segment, before widening = 1150 veh/day AADT on the highway segment, after widening = 1750 veh/day Proportion of total constituted by CMF-related crashes is 0.574. Answers: Expected average crash frequency after widening = total crashes/year Report your answers to the closest two decimal places without units (i.e., if your answer is 10.258, you should enter 10.26 or if your…
A 15 mile section of Kapayapaan Road had the following reported accidents for 6 years from 1992. It is required to compute the accident rates of all accidents
The number of crashes involving trucks (“truck crashes”) has continuously increased as thenumber of truck increases. To analyze the association of truck crash rates with the number oflanes, truck crash rates were compared between two-lane and multi-lane highways as shown inthe table below. Is the standard deviation of truck crash rates significantly higher for two-lanehighways than multi-lane highways?Note: Final answer should be either “The standard deviation of truck crash rates is significantlyhigher for two-lane than multi-lane highways” or “The standard deviation of truck crash rates isnot significantly higher for two-lane than multi-lane highways”.Truck crash rates (crashes/million vehicle-km)Site No. Two-lane highways Multi-lane highways12345670.2560.3420.8421.0210.3610.2620.8610.1880.3120.4210.2850.2250.183
A 1.5-mile section of a two-lane road has an AADT of 10,000. In a three-year period, there have been 6 fatal accidents and 12 non-fatal accidents. The state allows 350 accidents per 100 mvm for three years, of which 100 are fatal. For which value of confidence level, this highway is considered safe? If the following countermeasures are implemented: widening the existing lane by 2 feet, and widening the existing shoulder by 2 feet paved, and widening the clear zone by 5 feet, what will be the number of accidents reduced if the AADT became 12,000?
Need type answer 1.A highway section has an accident rate of 150 accidents per 100 mvk. If the mean accident rate for all sections is 55 per 100 mvk, and the standard deviation is 26 per 100 mvk,should the section under study be flagged as hazardous with 90 percent confidence? 2. A stretch of four-lane, two-way highway 5.0 km long has a traffic volume of 25,000 vehicles per day. If for the last three years, the total number of accidents recorded was 1,800, determine the accident rate per 99 mvk.
Using a surveillance camera, 15 vehicles were observed within 350 m section of the innermost lane of the North Luzon Expressway. Estimate the average spacing of these vehicles.
An urban arterial street segment 0.2 km long has an average annual daily traffic (AADT) of 15,400 veh/day. In a three-year period, there have been 8 crashes resulting in death and/or injuries and 15 involving property damage only. The statewide average crash experience for similar types of roadway is 375 per 100 mv-km for a three-year period of which 120 involved death and/or injury and 255 caused property damage only. Is the 0.2 km long street segment hazardous? In identifying hazardous locations, consider that a single death/injury crash is equivalent to three property damage crashes. Use a 95% confidence level. (Highway & Engineering Traffic Engineering, SI unit, N. Garber)
An engineer wishing to obtain the speed characteristics on a bypass around her city at a confidence level of 95%, and an acceptable limit of 1.0 mi/h collected a total of 130 spot speed samples and determined that the variance is 25 (mi/h)2 . Has the engineer met with all of the requirements of the study?