DtRoadConstants Class Reference

A container for constants that define the path of a vehicle on the road in terms of design-vehicles and design-drivers. More...

Public Member Functions
	~DtRoadConstants ()
Constants
! These functions proved access to individual constants. Override to change how the road path geometry is constructed (ie the curved paths) and what driving decisions assume about other drivers.
virtual double	maxDesignDriverLateralAcceleration_G () const
	Typical value (see AASHTO Green Book), civilian driver comfort level. More...
virtual double	maxDesignDriverSpeed () const
	This parameter helps determine the curve between segments when the bend is very slight. More...
virtual double	typicalMaxSpeedLimitExceedFactor () const
	This is the factor that is multiplied by the road speed limit to predict the maximum speed of another vehicle on the road, for purposes of computing how far away to look for an approaching vehicle. More...
virtual double	minDesignVehicleTurnRadius () const
	The smallest turn radius that the logic assumes for roads. More...
virtual double	maxDesignVehicleWidth () const
	Default value 2.44. More...
virtual double	maxDesignVehicleLength () const
	Default value 12.2. More...
virtual double	default1LaneSpeedLimit () const
	Speed limits assumed when the rail segment limit is just a default value. More...
virtual double	default2LaneSpeedLimit () const
	Default value 22.22. More...
virtual double	default3LaneSpeedLimit () const
	Default value 27.78. More...

Static Public Member Functions
static DtRoadConstants *	instance ()
	This method is used to access the constants. More...
static void	setStaticRoadConstants (DtRoadConstants *)

Protected Member Functions
	DtRoadConstants ()

Static Protected Attributes
static DtRoadConstants *	theRoadConstants
	The road constants are constant during run time. More...

Detailed Description

A container for constants that define the path of a vehicle on the road in terms of design-vehicles and design-drivers.

See also the road design constants used for interpreting road features in DtRoadSegment.

To use the constants, first get the static object containing the constants and then use the member functions. Ie

DtRoadConstants *c = DtRoadConstants::instance();
double maxG = c->maxDesignDriverLateralAcceleration_G();

Constructor & Destructor Documentation

DtRoadConstants::DtRoadConstants ( )

protected

DtRoadConstants::~DtRoadConstants

(

)

Member Function Documentation

static DtRoadConstants* DtRoadConstants::instance ( )

static

This method is used to access the constants.

static void DtRoadConstants::setStaticRoadConstants ( DtRoadConstants *  )

static

virtual double DtRoadConstants::maxDesignDriverLateralAcceleration_G ( ) const

inlinevirtual

Typical value (see AASHTO Green Book), civilian driver comfort level.

In Gs. This is used as an assumption about other drivers when making driving decisions.

Default value 0.15

virtual double DtRoadConstants::maxDesignDriverSpeed ( ) const

inlinevirtual

This parameter helps determine the curve between segments when the bend is very slight.

Default value 35.7

virtual double DtRoadConstants::typicalMaxSpeedLimitExceedFactor ( ) const

inlinevirtual

This is the factor that is multiplied by the road speed limit to predict the maximum speed of another vehicle on the road, for purposes of computing how far away to look for an approaching vehicle.

Default value 1.2

virtual double DtRoadConstants::minDesignVehicleTurnRadius ( ) const

inlinevirtual

The smallest turn radius that the logic assumes for roads.

This is the radius that paths will use at intersections, for example. In meters.

This should be about 8.37' for a 40' bus, which is an appropriate design target. However, small roads with sharp bends in them such as the hill road in VR-Village have smaller turn radii than this, and the driving path logic does not work correctly.

virtual double DtRoadConstants::maxDesignVehicleWidth ( ) const

inlinevirtual

Default value 2.44.

virtual double DtRoadConstants::maxDesignVehicleLength ( ) const

inlinevirtual

Default value 12.2.

virtual double DtRoadConstants::default1LaneSpeedLimit ( ) const

inlinevirtual

Speed limits assumed when the rail segment limit is just a default value.

The number of lanes here is the number of lanes in the road segment, i.e. the number in one direction. Note 60 kph = 16.67mps, 80kph = 22.22mps, 100kph = 27.78mps

Default value 16.67

virtual double DtRoadConstants::default2LaneSpeedLimit ( ) const

inlinevirtual

Default value 22.22.

virtual double DtRoadConstants::default3LaneSpeedLimit ( ) const

inlinevirtual

Default value 27.78.

Member Data Documentation

DtRoadConstants* DtRoadConstants::theRoadConstants

staticprotected

The road constants are constant during run time.

Only one copy is maintained, in this static variable.

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The documentation for this class was generated from the following file:

• /data/exports/nrhent7-1/nightly/docs/vrForces.vrf4-8-branch/include/vrfmodel/roadConstants.h