Download presentation

Presentation is loading. Please wait.

Published byClifton Lewis Modified about 1 year ago

1
Spot Speed Study

2
Before anything else Read the manual carefully. It is your homework What is covered in the following slides is just general

3
General The data is to be used for assessing general speed trends and for setting speed limits. The equipment for our data collection procedure is a hand-held radar. Radar usage Radar checkout

4
Data Collection Name of the safety officer Choose section of road Not close to intersection Off-peak period during daylight hours on a typical weekday Hide I will contact Police to cover you

5
Data collection form

6
Data analysis What should you do with the collected speeds? What else, statistical analysis! Remember that old stuff: Mean, standard deviation,… Plus a few more things

7
Speed Statistics Average speed Speed data Grouped Not grouped Standard deviation Speed data Grouped Not grouped Variances2s2 u = u j /N s = f(u i – u) 2 N - 1

8
Types of Speed Measurements Median speedThe speed at the middle value in a series of spot speeds. Or, 50 th -percentile speed Modal speedThe speed value that occurs most frequently in a sample of speeds i th -percentile speed The spot speed below which i percent of the vehicles travel, e.g. 85 th -percentile speed PaceThe range of speed that has the greatest number of observations; usually 10-mph range 50% 85%

9
Frequency histogram example

10
Frequency distribution curve

11
Cumulative frequency distribution curve

12
Helping calculation table

13
Interpret and conclude Answer questions in manual Prepare your presentation

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google