For a specific rural road segment in northeast Colorado, the total number of crashes as well as the number of fatal crashes have been recorded. Using the data provided with a traffic analysis within two standard deviations (or 95% confidence interval), determine if this site should be flagged for further study. Data: Length of road segment = 2 mi. AADT = 11,350 veh/day Total number of injury crashes for past 5 years = 55 Total number of fatal crashes for past 5 years = 5 Total number of property-only crashes for past 5 years = 100 Average number of statewide injury crashes for rural roads over past 5 years = 1.30 per 106 VMT Average number of statewide fatal crashes for rural roads over past 5 years = 0.02 per 106 VMT Average number of statewide property only crashes for rural roads over past 5 years = .033 per 106 VMT Weighted average crash rate of injury crashes for rural Colorado roads = 3 Weighted average crash rate of fatal crashes for rural Colorado roads = 8 Weighted average crash rate of property only crashes for rural Colorado roads = 1

For a specific rural road segment in northeast Colorado, the total number of crashes as well as the number of fatal crashes have been recorded. Using the data provided with a traffic analysis within two standard deviations (or 95% confidence interval), determine if this site should be flagged for further study. Data: Length of road segment = 2 mi. AADT = 11,350 veh/day Total number of injury crashes for past 5 years = 55 Total number of fatal crashes for past 5 years = 5 Total number of property-only crashes for past 5 years = 100 Average number of statewide injury crashes for rural roads over past 5 years = 1.30 per 106 VMT Average number of statewide fatal crashes for rural roads over past 5 years = 0.02 per 106 VMT Average number of statewide property only crashes for rural roads over past 5 years = .033 per 106 VMT Weighted average crash rate of injury crashes for rural Colorado roads = 3 Weighted average crash rate of fatal crashes for rural Colorado roads = 8 Weighted average crash rate of property only crashes for rural Colorado roads = 1

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

To measure the spot speed of vehicles on a certain accident-prone location along MacArthur Highway, a trap length equal to 40 m long was set. The times in seconds clocked by an observer for 24 vehicles were: (see table below). Determine the spot speed or time mean speed. If the maximum speed limit at the location was set at 60 kph, determine the percentage of drivers violating the regulation? (Note: This is just an illustrative problem; more data are actually needed for this kind of analysis.)
A traffic engineer urgently needs to determine the AADT on a rural primary road that has the volume distribution characteristics as discussed. She collected the data shown below on a Friday during the month of March. Determine the AADT of the road. 1:00 –2:00 p.m. = 600; 2:00 –3:00 p.m. = 645; 3:00 –4:00 p.m. = 730; 4:00 –5:00 p.m. = 780; 5:00 –6:00 p.m. = 815; 6:00 - 7:00 p.m. = 795
Consider only a single lane of a highway. Based on extensive data from an urban freeway it is assumed thatfree-flow speeds (i.e., there are no jams) can best be represented by a Normal distribution with mean andstandard deviation 119 km/h and 13.1 km/h, respectively.1. What is the probability that the speed of a randomly selected vehicle is between 100 and 120 km/h?2. What is the expected number of vehicles between two vehicles that exceed the posted speed limit of100 Km/h? You can use the Z table for calculating the final answer. You can also write your final answer in form ofR functions or as PDF/CDF of statistical distributions with correct arguments.
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
This is a three-part question. Data obtained from aerial photography showed eight vehicles on an 800 ft-long section of road. Traffic data collected at the same time indicated an average time headway of 3.7 sec. Part A. Determine the density on the highway in vehicles per mile. Part B. Determine the flow on the road in vehicles per hour. Part C. Determine the space mean speed in mph.
Speed data collected on an urban roadway yielded a standard deviation in speeds of 4.8 mi/h. (a) If an engineer wishes to estimate the average speed on the roadway at a 95% confidence level so that the estimate is within 2 mi/h of the true average, how many spot speeds should be collected? (b) If the estimate of the average must be within 1 mi/h, what should the sample size be?
7. The following are the tabulation of the coverage count of the average daily traffic on a monthly and weekly basis made with automatic traffic counts on a highway. Use the tables to calculate;(a) the ADT for February and October based on 2 days counts: (i) on Tuesday in February the daily counts were 250 vehicles and (ii) on Friday in October, the daily traffic volume was 300 vehicles. (b) the AADT if the flows counted on Friday, Saturday and Sunday in July were 8000, 6000 and 5000 vehicles on a 16 hourly count basis.(c) the seven day 16 hourly flow in September.
An engineer, wishing to determine the travel time and average speed along a sectionof an urban highway as part of an annual trend analysis on traffic operations, conducteda travel time study using the floating-car technique. He carried out 10 runs andobtained a standard deviation of ±3 mi/h in the speeds obtained. If a 5% significancelevel is assumed, is the number of test runs adequate?
For this question, you will be required to upload your approach and solution. Determine the AADT on a rural primary road for the following data: Time of day Volume 0600 - 0700 435 0700 - 0800 550 0800 - 0900 572 Data collected was on a Wednesday during the month of August.
Data on a traffic accident recorded on a certain intersection for the past 7 years has an accident rate of 4288 per million entering vehicles (ARMV). If the average daily traffic entering the intersection is 492, find the total number of accidents during the 7-year period
A stretch of four-lane, two-way highway 5.0 km long has a traffic volume of 35,000 vehicles per day. If for the last three years, the total number of accidents recorded was 1,900, determine the accident rate per 100 m
To study congestion in the core of a city, a survey measured traffic volume at a busy intersection between the hours of 1300 and 1600. Describe the bias that could influence the results of this survey. Suggest ways in which the survey could be redesigned to reduce the possibility of bias.