Attributes of conflict areas

No

Unique number

LinkA,

LinkB

LinkA, LinkB: Number and name of link with the conflict area

VisibLinkA,

VisibLinkB

Visibility link A, Visibility link B: Maximum distance at which an approaching vehicle can "see" the vehicles on the other link. As long as a vehicle is on a non-priority link still far away from the conflict area, it plans to stop as close as possible to it. Avoid values < 1 m to keep the vehicle moving.

In the Figure, the blue vehicle at the bottom on link B has reached the point from where it can fully "see" past the blue building on link A where the red vehicle is (on the left). This means the visibility for link 2 = dL2.

Status

Identification of right of way by colors:

• A has right of way: Link A green - Link B red
• B has right of way: Link A red - Link B green
• Undetermined: Link A red - Link B red, for branching conflicts, so that vehicles can "see" each other. There is no intersection control, as vehicles simply remain in their original sequence.
• Passive: Link A amber - Link B amber, passive conflicat area without intersection control

FrontGapDef

FrontGap

Front gap (default):

• For the types Merge and Crossing: Minimum gap time in seconds between the rear end of a vehicle in the major flow and the front end of a vehicle in the minor flow. Default 0.5 seconds To adhere to the minimum gap time, the yielding vehicle slows down as it approaches the conflict area and stops in front it, as long as the vehicle that has priority is front of or in the conflict area. Once the vehicle with the right of way has left the conflict area, the yielding vehicle can enter it and no longer takes the Front gap into account.
• Into the Gaps list on the right, you can enter the minimum gap time FrontGap per vehicle class.

The figure below shows the current situation (the non-transparent vehicles - upstream) and the future situation (the semi-transparent vehicles - upstream). In the future situation, the vehicle in the major flow has just left the conflict area. Up until this time, the Front gap is considered the time required by the vehicle in the minor flow to reach the empty conflict area (in this case: 0.5s)

RearGapDef

RearGap

Rear gap (default): Only for type Crossing:

• Minimum gap time in seconds between the rear end of a vehicle in the minor flow and the front end of a vehicle in the major flow. This is the time that must be provided, after a yielding vehicle has left the conflict area and before a vehicle with the right of way enters it. Default 0.5 seconds The conflict area detects vehicles within a range of at least 100 meters. This distance is computed based on a constant value of 5 seconds and the speed of the vehicle.
• Into the Gaps list on the right, you can enter the minimum gap time per vehicle class.

The figure shows the current situation (vehicles darker in color - upstream) and the future situation (as light, semi-transparent vehicles - upstream), once the vehicle in the major flow has reached the conflict area. The rear gap is evaluated as the time that has elapsed since the vehicle in the minor flow has left the conflict area (in this case: 0.7s).

MinGapBlockDef

MinGapBlock

Minimum gap blocking (default): Only applies if the attribute Avoid blocking the major flow is not selected and thus a yielding vehicle may enter the conflict area, blocking the major flow:

• Default minimum gap time for the yielding vehicle for entry before the vehicle with the right of way. Minimum gap blocking (default) is used for all vehicles that are not part of a vehicle class for which a class-specific gap time has been defined. Default 3.0 s
• Into the Gaps list on the right, you can enter the Minimum gap blocking per vehicle class.

Pedestrians utilize the Minimum gap blocking attribute to decide whether they enter the conflict area before a vehicle with the right of way.

MesoCriticGap

Meso critical gap: Edit this value in the Meso turn conflicts list or in the coupled list Nodes - Meso turn conflicts (Attributes of meso turn conflicts), (Attributes of nodes).

SafDistFactDef

Safety distance factor: only for the type Merge: This factor is multiplied with the normal desired safety distance of a vehicle in the major flow in order to determine the minimum distance a vehicle of the yielding flow must keep when it is completely in the conflict area of type Merge.

Into the Gaps list on the right, you can enter the safety distance factor per vehicle class.

The figure below shows identical situations, but with different factors: top = 1.0, bottom = 0.5. This is why the blue vehicle (bottom) can still enter the conflict area, while the red vehicle (top) has to stop.

In the figure, the relevant part of the safety distance is highlighted in yellow:

AddStopDist

Additional stop distance: only relevant for vehicles or pedestrians required to wait: Distance in meters where pedestrians or vehicles must wait upstream of the conflict area if they have to yield the right of way. As a result, vehicles or pedestrians are required to stop further away from the conflict area and thus also have to travel a longer distance to pass this area. Default value 0 m: The stop line position is immediately upstream of the start point of the conflict area in the direction of travel.

The additional stop distance describes the upstream position on the link at which the pedestrians or vehicles have to wait if they have to yield the right of way. You can position the stop line upstream from the regular stop line of the conflict area.

ObsAdjLns

Observe adjacent lanes:  If this option is selected, at merging conflicts, incoming vehicles of the minor flow that are required to yield will account for the vehicles in the major flow that want to change to the conflicting lane. Vehicles that have already started changing lanes and want to change to the lane with the conflict are taken into account. Vehicles that have not yet started changing lanes are not taken into account.

This option reduces the simulation speed.

AnticipRout

Anticipate routes: Percentage of vehicles required to yield that account for the routes of vehicles with the right of way. These are approaching with the major flow and will turn further upstream. They will thus not reach the conflict area. For example, you can use it to determine the percentage of vehicles that enter a roundabout in reality because they trust the priority vehicle to exit the roundabout before it reaches the conflict area, based on the set turn signal of the priority vehicle. Value range 0 to 100 %, default value 0 %

The attribute has no effect on pedestrians who do not have to wait. For pedestrians who are required to wait, the following applies:

• 100%: All pedestrians required to wait observe the routes of approaching vehicles with the right of way in the major flow.
• < 100%: Pedestrians required to wait do not observe the routes of approaching vehicles with the right of way in the major flow.

AvoidBlockMinor

Avoid blocking the minor flow: If a vehicle with the right of way belongs to the percentage rate selected, it will check the space available downstream of the conflict area and does not drive into the conflict area under the following conditions:

• when the space available downstream of the conflict area is less than the total of the individual vehicle length + 0.5 m and the blocking vehicle is slower than 5 m/s and slower than 75% of its desired speed
• when the obstacle is a red signal

AvoidBlockMajor

Avoid blocking the major flow

•  If this option is selected, a yielding vehicle does not enter or stop within the conflict area, unless it can drive through it in one go. The option is selected by default. For the yielding vehicle, the attribute Minimum gap blocking is not taken into account.
•  If this option is not selected, a yielding vehicle can enter and stop within the conflict area, even if it cannot drive into the following lane conflict, as it is blocked by a vehicle that has the right of way. In this case, the yielding vehicle might block the major flow. For the yielding vehicle, the attribute Minimum gap blocking is taken into account.

Example: You are modeling a long conflict area between a vehicle route and a very wide pedestrian route with many narrow lanes and with a priority for pedestrians. Deactivate the option to let a vehicle successively drive into and traverse the lane conflicts without having to wait for a time when it can drive through the entire conflict area, and possibly other conflict areas lying close behind it, in one go.

ConflTypDetmAuto:

•  If this option is selected, Vissim automatically determines the conflict type based on whether links intersect or connectors begin or end on the link.
•  If this option is not selected, in the Attributes list, in the Conflict type (manual) column, the text box is no longer hatched and you can select the conflict type.

ConflTypMan: Select conflict type (Using conflict areas):

• Merge
• Branching
• Crossing

A conflict type is valid for all lanes of a conflict area. You cannot select different conflict types within a conflict area.