Positive Positive Guidance Guidance PrinciplesPrinciples

Positive guidance Positive guidance conceptconcept

- Provide drivers sufficient Provide drivers sufficient information about roadway information about roadway design, operations, and potential design, operations, and potential hazards so they respond correctly hazards so they respond correctly and avoid crashesand avoid crashes

CE 552 objectives related CE 552 objectives related to PGto PG

Identify problemsIdentify problems

Crash data, complaint files, site diagramsCrash data, complaint files, site diagrams Analyze driver tasks / performanceAnalyze driver tasks / performance

On-site speed and driver studiesOn-site speed and driver studies Assess the current information systemAssess the current information system

Road safety audits a portion of thisRoad safety audits a portion of this Develop and evaluate improvements or Develop and evaluate improvements or

modifications to the information systemmodifications to the information system

Driving Task Driving Task ComponentsComponents

Navigation Navigation

GuidanceGuidance

ControlControl Class - what are the elements of Class - what are the elements of

each?each?

Navigation componentsNavigation components

Route selectionRoute selection Distance to destinationDistance to destination Interchange / route change locationsInterchange / route change locations Directions of roadwaysDirections of roadways

- i.e. general elements associated - i.e. general elements associated with trip planningwith trip planning

GuidanceGuidance

Vehicle operator is in decision mode Vehicle operator is in decision mode regarding lane placement, speed and regarding lane placement, speed and more while considering existing:more while considering existing:

Horizontal and vertical alignmentHorizontal and vertical alignment Roadway cross sectionsRoadway cross sections Roadside obstaclesRoadside obstacles Traffic signage / controlsTraffic signage / controls Traffic features - volume _ speedsTraffic features - volume _ speeds

ControlControl

Driver in reactionary modeDriver in reactionary mode receives input from senses relating receives input from senses relating

to vehicle handlingto vehicle handling superelevationsuperelevation pavement texture pavement texture speed / accelerationspeed / acceleration

Examine Guidance sectionExamine Guidance sectionTraffic controls and human Traffic controls and human

factorsfactors D_R_D_R related to information or D_R_D_R related to information or

control signscontrol signs 1) D R D R distances1) D R D R distances 2) Ability to read and recall 2) Ability to read and recall

information / information / driver visual acuity driver visual acuity

3) Primacy3) Primacy 4) Expectancy 4) Expectancy 5) Redundancy5) Redundancy

Principle of PrimacyPrinciple of Primacy

concept of primacy asserts that concept of primacy asserts that at any at any givengiven

moment, some information is more moment, some information is more important than other information. important than other information.

Control information is more Control information is more important than guidance information important than guidance information

Guidance information is more Guidance information is more important than navigation information.important than navigation information.

Information about some hazards is Information about some hazards is more important than information about more important than information about other hazards.other hazards.

Principle of ExpectancyPrinciple of Expectancy Expectancy affects the perception and Expectancy affects the perception and

use of information. People expect use of information. People expect certain things to appear and operate in certain things to appear and operate in certain ways.certain ways.

Where do expect to find the light switch?Where do expect to find the light switch? Move switch up or down to turn light Move switch up or down to turn light

on?on? Hot water on left or right?Hot water on left or right?

Turn clockwise or counter-clockwise to Turn clockwise or counter-clockwise to shut water off? (Tougher question )shut water off? (Tougher question )

Principle of ExpectancyPrinciple of Expectancy

Hot water on left or right?Hot water on left or right? Turn clockwise or counter-clockwise Turn clockwise or counter-clockwise

to shut water off? (Tougher to shut water off? (Tougher question )question )

Principle of ExpectancyPrinciple of Expectancy

How does this relate to highway safety How does this relate to highway safety design and controls?design and controls?

Exit ramps - _______Exit ramps - _______

Color red - ________Color red - ________

Curve sign or turn sign - Curve sign or turn sign - ______________________________

Chevron to indicate lane shift - Chevron to indicate lane shift - ______________________

Principle of RedundancyPrinciple of Redundancy

Recognize that different driver’s pick Recognize that different driver’s pick up cues in different ways AND short up cues in different ways AND short term memory is term memory is short, short, additional additional input is neededinput is needed

Example: Example:

Redundancy by _________________Redundancy by _________________

Analysis zones in Positive Analysis zones in Positive GuidanceGuidance