Lane Attributes Model

Lane Direction of Travel

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Direction of Travel

Definition: Lane Direction of Travel reflects the direction of traffic flow in a Lane. It must be consistent with traffic flows, legal regulations, and the related road link's Direction of Travel.

Values:

• UNKNOWN
• BOTH: bidirectional
• FORWARD: same as Lane Group orientation
• BACKWARD: opposite to Lane Group orientation
• NONE: no direction for medians, shoulders, and other non-drivable lanes

Lane Type

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Type

Definition: Lane Type indicates special designations that affect how traffic uses a Lane.

Values:

• LANE_TYPE_UNKNOWN: A lane that has not yet been coded with a lane type, or does not meet inclusion rules, or a lane type not supported in this version of the schema.
• REGULAR: a Lane that is used for standard traffic, and not designated as any other Lane type.
• HIGH_OCCUPANCY_VEHICLE: Reserved for HOV traffic, at some times or all times.
• DRIVABLE_SHOULDER: a Lane that is designated as a Shoulder at certain times, but usable as a traffic Lane at other times.
• BICYCLE: for bicycles only, as typically indicated by signs and/or barriers to larger vehicles.
• PARKING: lanes running parallel to driving lanes, but reserved solely for parking.
• REVERSIBLE: A lane where the lanes direction of travel changes during specific times to manage traffic flow.
• EXPRESS: A dedicated lane used for faster moving traffic and with fewer entrances and exits.
• ACCELERATION: A dedicated or designated lane that allows a vehicle to increase its speed to a point where it can safely merge with traffic.
• DECELERATION: A dedicated or designated lane that allows a vehicle to decrease its speed to where it can safely stop or turn and not affect ongoing traffic.
• AUXILIARY: A dedicated or designated lane that is used as both an acceleration and deceleration lane between multiple entrance and exit ramps.
• SLOW: A lane that is provided/designated on long and/or steep uphill stretches of high-speed roads to enhance the ability of vehicles that can maintain speed up the incline to pass those vehicles (typically heavy trucks) that cannot.
• PASSING: A lane added to bidirectional roads where passing needs to be regulated for safety.
• REGULATED_ACCESS: A lane used to regulate traffic using time intervals.
• TURN: A lane used to regulate traffic using time intervals.
• CENTRE_TURN: A lane in the center of a bi-directional road that allows vehicles to slow down and/or wait to make turns across oncoming lanes of traffic. Center Turn Lanes allow traffic to make turns from either direction of travel without disrupting traffic flow.
• TRUCK_PARKING: A lane provided for truck parking.
• SHOULDER: A full-time Shoulder, which is not intended for traffic usage at any time.
• VARIABLE_DRIVING: Lanes added to a road that open and close to accommodate traffic flow using variable indicators/electronic controls, but marked differently from Drivable Shoulders.
• DRIVABLE_PARKING: A lane that exists on the roadbed, parallel to the driving lanes, and is typically used for parking; however, it may allow vehicles to use it as a driving lane at times.
• OTHER: A lane that is not accessible for autos or HOVs, and vehicles (e.g., taxis, buses, trucks) other than Emergency Vehicles are allowed.
• BUS: Typically only allows bus travel, as indicated by lane markings, signs, buffers, or barriers.

Lane Transition Type (Status)

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Transition Type (Status)

Definition: The Lane Transition Type (a.k.a. Lane Transition Status) attribute indicates whether a Lane is forming or ending, relative to the Lane's normal direction of travel. This attribute is published only for Lanes marked as in transition within a Lane Group.

Values:

• Split
• Merge

Lane Width Profile

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Width Profile

Definition: This attribute describes the properties of lane width.

Values:

• min_width_cm
• max_width_cm
• profile_relative_min_location
• profile_relative_max_location

Lane Width Restriction

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Width Restriction

Definition: Lane Width Restriction identifies the width of a lane when it is different from standard lane widths on the road.

• Included posted vehicle width restriction is applicable to a subset of lanes when it is different than the lane width restrictions applied to the road.
• All lanes that apply to the posted sign get the Lane width Restriction attribute.
• Unit of measure is based on the metric system, globally, in centimeter with zero precision.
• The textual information is not included.

Lane Height Restriction

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Height Restriction

Definition: Lane Height Restriction identifies the existence of a height restriction for a lane, limiting access to vehicles exceeding a specific height.

• Included if either of the following conditions is met: 1) If a posted height sign is applicable to a subset of lanes on a link; 2)If all lanes in the travel direction have differing height signs posted.
• All lanes that apply to the posted sign get the Lane height Restriction attribute with a value.
• Unit of measure is based on the metric system, globally, in centimeter with zero precision.
• If multiple height signs are posted through consecutive overpasses, then the following apply: 1) If all lanes have a height sign posted, and the "through path" lane has the same height posted, then one Lane Height is added across both overpasses; 2) If all lanes have a height sign posted, and the "through path" has different heights posted, then one Lane Height is added across both overpasses with the lowest height posted along the path. (Note: consecutive overpasses indicate that the driver must pass under multiple overpasses, but there is only one exit prior to them (not all have an exit).

Lane Speed Limit

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Speed Limit

Definition: The "speed_limit_override" attribute is set only where the lane speed limit is different from the associated road speed limit. Notes:

• Posted signs and markings on the pavement signify a lane specific speed limit.
• Speed limits are captured for a specific lane for all vehicle types (automobiles, buses, carpools, deliveries, taxis, through traffic, trucks). This includes exit lanes, HOV lanes, and drivable shoulder lanes.
• If all of the lanes on a road in one direction of travel have the same speed limit, then the Lane Speed Limit is not included.
• Ramp speed limits apply to the ramp only, and not the highway. Speed limits that apply to a lane before a ramp are included. Ramp speed limits are mostly captured on the road link since they are typically a single lane.

Values (same as Road Speed Limit):

• Speed, an integer value. 0 if unknown or unlimited
• Unlimited: if present, there is no maximum legal speed
• Units: indicates whether the Speed Limit is in miles per hour or kilometers per hour
• SpeedLimitSource

Lane-Level Variable Speed Limit

Topology Reference Type: Lane Parametric Range

Format Reference: Lane-Level Variable Speed Limit

Lane-level Variable Speed Limit defines the extent of the lane for which a posted Variable Speed Sign is applicable.

This condition sets the parametric range for the presence of an electronic speed limit sign and the lanes the speed limit applies to. The speed limit applies until the variable speed limit ends per a posted sign, or until the speed limit is replaced by a posted sign.

• A condition modifier for Lane Access Characteristics is used if the speed limit applies to certain vehicle types.
• Conforms to the access characteristics noted in Lane Access Characteristics, documented below.
• All lanes where the speed limit applies should be continuous, without gaps, until the speed limit terminates.
• Applied to ramps and highway-to-highway connectors if the sign is posted on the split point and intended for that specific lane.
• Not applied to lanes associated with:
  • Rest areas
  • Weigh stations
  • Roundabouts
  • Special Traffic Figure
  • Across country borders

Lane-Level Variable Speed Sign

Topology Reference Type: Lane Parametric Range

Format Reference: Lane-Level Variable Speed Sign

Lane-level Variable Speed Sign identifies the of location a typically automated sign where the posted speed limit can vary, and identifies which lane that speed limit applies to over a validity range.

Lane-Level Usage Fee Required

Topology Reference Type: Lane Parametric Range

Format Reference: Lane-Level Usage Fee Required

The Lane-Level Usage Fee Required condition identifies the lanes that require payment for use, the Lane Access Characteristics to which the toll applies, and the type of toll feature it represents. Lane-Level Usage Fee Required also identifies the Toll System Type, if applicable. The Date/Time condition is applied if the toll is in effect only on specific days or during specific times of day.

Lane-Level Vehicle Checkpoint

Topology Reference Type: Lane Parametric Range

Format Reference: Lane-Level Vehicle Checkpoint

The Lane-Level Vehicle Checkpoint condition classifies SENTRI lanes at a Vehicle Checkpoint, specifically at Border Crossings in the US. SENTRI (Secure Electronic Network for Travelers Rapid Inspection) identifies the type of lane for rapid inspection by US Customs.

Specifically, this condition identifies lanes that have a different condition than the road attribute, or if a sign identifies this specific condition. This includes the presence of a vehicle checkpoint at any locations (except ferry terminals) or automatic controls.

Lane Transition Area

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Transition Area

Lane Transition Area indicates lanes that are in an area where one or more lanes are forming or ending, and lane markings are not present on the road surface. It also indicates where lane markings are present, but the lane markings do not clearly indicate where lanes are forming or ending.

Lane Access Characteristics

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Access Characteristics

Definition: The "accessible_by" attribute in Lane Access Characteristics defines situations where certain vehicle types are allowed on a road, but are not allowed in at least one of the road's lanes. Lane Access Characteristics, when present on a lane, override the road's link-level Access Characteristics for this lane. Any vehicle type that can use some lane on the road link is included (set to "Yes") at the road level. Notes:

• A lane that allows all the vehicle types on the road link does not have Lane Access Characteristics defined.
• A lane that allows some but not all of those vehicle types has Lane Access Characteristics: The vehicle types that can use the lane are set to "Yes". (A lane cannot grant access to a vehicle type that is not allowed on its Road Link.) The vehicle types that cannot use a lane are set to "No." This includes vehicle types explicitly prohibited on this lane, as well as the vehicle types that are not permitted on the road link.
• The restrictions implied by Lane Access Characteristics are full-time. If a vehicle type has limited use of the lane, such as restricted to certain dates/times, this restriction is not used, but instead uses the Lane Access Restriction Condition.

Values for lane access are the same values for road access, which are determined by the RoadUsers enum.

Lane Surface Markings

Topology Reference Type: Lane Parametric Point

Format Reference: Lane Surface Markings

Point attributes, positioned using the lateral projection of the marking's center point relative to the lane drive path, represent lane surface markings of the types indicated below:

• Stop Lines
• Crosswalks
• Yield Indications
• Signs, Icons and Text painted on road surfaces (e.g. the speed limit in lane, indication of a bicycle or bus-only lane, etc.)
• Arrows of various kinds (e.g arrow right, arrow left, etc.), other than Lane Boundary Markings, that show the direction of travel per lane.

Lane Within an Intersection

Topology Reference Type: Lane Parametric Range

Format Reference: Lane Within an Intersection

Description: Lane within an Intersection indicates lane groups that are part of an intersection between navigable roads. (Pedestrian paths and walkways are not considered intersections.)