Author: Susan C. Paulus
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
In this thesis, the author developed a retroreflective sheeting selection technique for traffic signs. Previous research was used to determine the luminance needed by drivers (demand luminance). The author used roadways scenarios to determine the amount of luminance the retroreflective sheeting on a sign would produce (supply luminance). A spreadsheet was developed to determine the performance of different retroreflective sheeting types by comparing the demand and supply luminance for specific roadway scenarios. Using the results of previous studies, three demand luminance levels were created: replacement, adequate, and desirable. The replacement level represents the level of luminance when a sign needs to be replaced and is 2.5 cd/m2. The adequate level is the recommended amount of luminance when installing new traffic signs and is 10 cd/m2. The desirable level is the approximate level when additional luminance has diminishing returns and is 30 cd/m2. Supply luminance on a specific traffic sign was determined by evaluating roadway geometries, sign placement, retroreflective sheeting type and vehicle data. The author reviewed roadway geometries in Texas to estimate typical number of lanes, shoulder widths and horizontal curvature in the US. Sign placement from the MUTCD determined the typical lateral placements, sign heights, and sign twists. Vehicle data included vehicle dimensions and headlamp type. Both the supply and demand luminance were determined for a specific viewing distance for a given scenario. The viewing distance is the distance a driver needs to read or recognize a sign to respond properly. In addition, the type of sign, alphanumeric or symbol, determined how this distance was calculated. The author developed four sign groups to calculate the distance required to read and respond to a traffic sign, including 1) Stop required, 2) Reduction in speed required, 3) Read the message provided, and 4) Change of lane required. For symbol signs, the minimum required visibility distance (MRVD) was determined for the sign group and for text signs, the viewing distance at a legibility index (LI) of 30 ft/in was found. At these distances, the author calculated the supply luminance and then compared it to the demand luminance levels to determine the performance level. The author developed the Retroreflective Sheeting Selection Spreadsheet (RSSS) to allow others to use the methodology presented in this thesis. RSSS allows users to input the roadway data, vehicle data, and sign data. RSSS takes this information and looks up the supply luminance for the scenario. RSSS then compares the supply luminance to the demand luminance levels and outputs the retroreflective sheeting performance level for the scenario.
A Retroreflective Sheeting Selection Technique for Nighttime Drivers' Needs
Author: Susan C. Paulus
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
In this thesis, the author developed a retroreflective sheeting selection technique for traffic signs. Previous research was used to determine the luminance needed by drivers (demand luminance). The author used roadways scenarios to determine the amount of luminance the retroreflective sheeting on a sign would produce (supply luminance). A spreadsheet was developed to determine the performance of different retroreflective sheeting types by comparing the demand and supply luminance for specific roadway scenarios. Using the results of previous studies, three demand luminance levels were created: replacement, adequate, and desirable. The replacement level represents the level of luminance when a sign needs to be replaced and is 2.5 cd/m2. The adequate level is the recommended amount of luminance when installing new traffic signs and is 10 cd/m2. The desirable level is the approximate level when additional luminance has diminishing returns and is 30 cd/m2. Supply luminance on a specific traffic sign was determined by evaluating roadway geometries, sign placement, retroreflective sheeting type and vehicle data. The author reviewed roadway geometries in Texas to estimate typical number of lanes, shoulder widths and horizontal curvature in the US. Sign placement from the MUTCD determined the typical lateral placements, sign heights, and sign twists. Vehicle data included vehicle dimensions and headlamp type. Both the supply and demand luminance were determined for a specific viewing distance for a given scenario. The viewing distance is the distance a driver needs to read or recognize a sign to respond properly. In addition, the type of sign, alphanumeric or symbol, determined how this distance was calculated. The author developed four sign groups to calculate the distance required to read and respond to a traffic sign, including 1) Stop required, 2) Reduction in speed required, 3) Read the message provided, and 4) Change of lane required. For symbol signs, the minimum required visibility distance (MRVD) was determined for the sign group and for text signs, the viewing distance at a legibility index (LI) of 30 ft/in was found. At these distances, the author calculated the supply luminance and then compared it to the demand luminance levels to determine the performance level. The author developed the Retroreflective Sheeting Selection Spreadsheet (RSSS) to allow others to use the methodology presented in this thesis. RSSS allows users to input the roadway data, vehicle data, and sign data. RSSS takes this information and looks up the supply luminance for the scenario. RSSS then compares the supply luminance to the demand luminance levels and outputs the retroreflective sheeting performance level for the scenario.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
In this thesis, the author developed a retroreflective sheeting selection technique for traffic signs. Previous research was used to determine the luminance needed by drivers (demand luminance). The author used roadways scenarios to determine the amount of luminance the retroreflective sheeting on a sign would produce (supply luminance). A spreadsheet was developed to determine the performance of different retroreflective sheeting types by comparing the demand and supply luminance for specific roadway scenarios. Using the results of previous studies, three demand luminance levels were created: replacement, adequate, and desirable. The replacement level represents the level of luminance when a sign needs to be replaced and is 2.5 cd/m2. The adequate level is the recommended amount of luminance when installing new traffic signs and is 10 cd/m2. The desirable level is the approximate level when additional luminance has diminishing returns and is 30 cd/m2. Supply luminance on a specific traffic sign was determined by evaluating roadway geometries, sign placement, retroreflective sheeting type and vehicle data. The author reviewed roadway geometries in Texas to estimate typical number of lanes, shoulder widths and horizontal curvature in the US. Sign placement from the MUTCD determined the typical lateral placements, sign heights, and sign twists. Vehicle data included vehicle dimensions and headlamp type. Both the supply and demand luminance were determined for a specific viewing distance for a given scenario. The viewing distance is the distance a driver needs to read or recognize a sign to respond properly. In addition, the type of sign, alphanumeric or symbol, determined how this distance was calculated. The author developed four sign groups to calculate the distance required to read and respond to a traffic sign, including 1) Stop required, 2) Reduction in speed required, 3) Read the message provided, and 4) Change of lane required. For symbol signs, the minimum required visibility distance (MRVD) was determined for the sign group and for text signs, the viewing distance at a legibility index (LI) of 30 ft/in was found. At these distances, the author calculated the supply luminance and then compared it to the demand luminance levels to determine the performance level. The author developed the Retroreflective Sheeting Selection Spreadsheet (RSSS) to allow others to use the methodology presented in this thesis. RSSS allows users to input the roadway data, vehicle data, and sign data. RSSS takes this information and looks up the supply luminance for the scenario. RSSS then compares the supply luminance to the demand luminance levels and outputs the retroreflective sheeting performance level for the scenario.
Sign Luminance Requirements for Various Background Complexities
Author: Douglas J. Mace
Publisher:
ISBN:
Category : Reflective materials
Languages : en
Pages : 48
Book Description
The Federal standards (FP-79) for luminance of retroreflective materials for traffic signs are acceptance standards; they provide no differentiation based on driver need. Driver needs for sign luminance are of 3 types -- luminance for sign comprehension, luminance levels that define sign legibility, and luminance levels for sign conspicuity. This study was directed toward establishing, for different levels of scene complexity, luminance levels for conspicuity of yellow diamond warning signs at night. A procedure based upon rating sign locations on 4 scales was useful for identifying low complexity and high complexity scenes.
Publisher:
ISBN:
Category : Reflective materials
Languages : en
Pages : 48
Book Description
The Federal standards (FP-79) for luminance of retroreflective materials for traffic signs are acceptance standards; they provide no differentiation based on driver need. Driver needs for sign luminance are of 3 types -- luminance for sign comprehension, luminance levels that define sign legibility, and luminance levels for sign conspicuity. This study was directed toward establishing, for different levels of scene complexity, luminance levels for conspicuity of yellow diamond warning signs at night. A procedure based upon rating sign locations on 4 scales was useful for identifying low complexity and high complexity scenes.
Nationally Coordinated Program of Highway Research, Development, and Technology
Author:
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 100
Book Description
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 100
Book Description
Transportation Research Record
Author:
Publisher:
ISBN:
Category : Air travel
Languages : en
Pages : 656
Book Description
Publisher:
ISBN:
Category : Air travel
Languages : en
Pages : 656
Book Description
Managing Selected Transportation Assets
Author: Michael J. Markow
Publisher: Transportation Research Board
ISBN: 0309097894
Category : Airports
Languages : en
Pages : 199
Book Description
NCHRP synthesis 371 explores the state of the practice for managing transportation infrastructure assets other than pavements and bridges, and documents gaps in knowledge and areas in need of potential further study.
Publisher: Transportation Research Board
ISBN: 0309097894
Category : Airports
Languages : en
Pages : 199
Book Description
NCHRP synthesis 371 explores the state of the practice for managing transportation infrastructure assets other than pavements and bridges, and documents gaps in knowledge and areas in need of potential further study.
Freeway Guide Sign Replacement
Author: Hugh W. McGee
Publisher: Transportation Research Board
ISBN: 9780309049023
Category : Transportation
Languages : en
Pages : 52
Book Description
This synthesis will be of interest to traffic engineers, planners, and others interested in making sure that motorists' needs for directional information on freeways are being met. Information is provided on policies and procedures used by states in evaluating freeway guide signs and replacing those that are outdated or deteriorated. Many signs on freeways and other controlled-access highways have exceeded their service life and are no longer serving motorists' needs. This report of the Transportation Research Board describes the policies, proceduress, and criteria used by states for freeway sign evaluation and replacement programs.
Publisher: Transportation Research Board
ISBN: 9780309049023
Category : Transportation
Languages : en
Pages : 52
Book Description
This synthesis will be of interest to traffic engineers, planners, and others interested in making sure that motorists' needs for directional information on freeways are being met. Information is provided on policies and procedures used by states in evaluating freeway guide signs and replacing those that are outdated or deteriorated. Many signs on freeways and other controlled-access highways have exceeded their service life and are no longer serving motorists' needs. This report of the Transportation Research Board describes the policies, proceduress, and criteria used by states for freeway sign evaluation and replacement programs.
Nighttime Legibility of Ground-mounted Traffic Signs as a Function of Font, Color, and Retroreflective Sheeting Type
Author: Susan T. Chrysler
Publisher:
ISBN:
Category : Legibility (Printing)
Languages : en
Pages : 80
Book Description
A closed course nighttime legibility study measured legibility distance for 6-in. letters using Highway Series D and two experimental fonts, Clearview Condensed Road and a D-Modified font. The Clearview font has a thinner stroke width than Series D and was used for white-on-green signs. The D-Modified font has a thicker stroke width than Series D and was used for black letters on white, yellow, and orange backgrounds. Three types of retroreflective sheeting were tested: ASTM Types III, VIII, and IX.
Publisher:
ISBN:
Category : Legibility (Printing)
Languages : en
Pages : 80
Book Description
A closed course nighttime legibility study measured legibility distance for 6-in. letters using Highway Series D and two experimental fonts, Clearview Condensed Road and a D-Modified font. The Clearview font has a thinner stroke width than Series D and was used for white-on-green signs. The D-Modified font has a thicker stroke width than Series D and was used for black letters on white, yellow, and orange backgrounds. Three types of retroreflective sheeting were tested: ASTM Types III, VIII, and IX.
Guidelines for Nighttime Visibility of Overhead Signs
Author: Paul John Carlson
Publisher:
ISBN: 9780309375474
Category : Traffic signs and signals
Languages : en
Pages : 84
Book Description
Chapter 1. Introduction -- chapter 2. Background -- chapter 3. Closed-course study -- chapter 4. Open-Road study -- chapter 5. Research findings -- References -- appendix A. Incremental effects of light sources and sign sheeting on legend luminance for overhead guide signs -- appendix B. Assessment of background complexity using digital images of roadway scenes by image processing -- appendix C. Open-road study details -- appendix D. Guidelines for Nighttime overhead sign visibility.
Publisher:
ISBN: 9780309375474
Category : Traffic signs and signals
Languages : en
Pages : 84
Book Description
Chapter 1. Introduction -- chapter 2. Background -- chapter 3. Closed-course study -- chapter 4. Open-Road study -- chapter 5. Research findings -- References -- appendix A. Incremental effects of light sources and sign sheeting on legend luminance for overhead guide signs -- appendix B. Assessment of background complexity using digital images of roadway scenes by image processing -- appendix C. Open-road study details -- appendix D. Guidelines for Nighttime overhead sign visibility.
Guidelines for Design and Operation of Nighttime Traffic Control for Highway Maintenance and Construction
Author: James E. Bryden
Publisher: Transportation Research Board
ISBN: 0309067650
Category : Automobile driving at night
Languages : en
Pages : 131
Book Description
Publisher: Transportation Research Board
ISBN: 0309067650
Category : Automobile driving at night
Languages : en
Pages : 131
Book Description
Synthesis of Highway Practice
Author: National Cooperative Highway Research Program
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 644
Book Description
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 644
Book Description