diff --git a/gtfs-realtime/proto/gtfs-realtime.proto b/gtfs-realtime/proto/gtfs-realtime.proto
index e050fc19..b2ee4a34 100644
--- a/gtfs-realtime/proto/gtfs-realtime.proto
+++ b/gtfs-realtime/proto/gtfs-realtime.proto
@@ -591,6 +591,29 @@ message VehiclePosition {
     // This message/field is still experimental, and subject to change. It may be formally adopted in the future.
     optional uint32 carriage_sequence = 5;
 
+    // Experimental: The number of cyclist positions currently available on
+    // this specific carriage. Cyclist positions are designated locations
+    // where cyclists can secure their bicycle or similar personal transport
+    // device.
+    // A value of 0 indicates no cyclist positions are currently available
+    // on this carriage.
+    // Absence of this field indicates cyclist position data is not
+    // available for this carriage.
+    // This message/field is still experimental, and subject to change. It
+    // may be formally adopted in the future.
+    optional uint32 cyclist_positions_available = 6;
+
+    // Experimental: The total number of cyclist positions (rack spaces,
+    // interior hooks, or designated storage areas) on this specific
+    // carriage. This represents the maximum capacity for bicycles on this
+    // carriage, regardless of current availability.
+    // A value of 0 indicates this carriage has no cyclist positions.
+    // Absence of this field indicates total cyclist position data is not
+    // available for this carriage.
+    // This message/field is still experimental, and subject to change. It
+    // may be formally adopted in the future.
+    optional uint32 total_cyclist_positions = 7;
+
     // The extensions namespace allows 3rd-party developers to extend the
     // GTFS Realtime Specification in order to add and evaluate new features and
     // modifications to the spec.
@@ -611,6 +634,34 @@ message VehiclePosition {
   // This message/field is still experimental, and subject to change. It may be formally adopted in the future.
   repeated CarriageDetails multi_carriage_details = 11;
 
+  // Experimental: The number of cyclist positions currently available on or
+  // in this vehicle. Cyclist positions are designated locations where
+  // cyclists can secure their bicycle or similar personal transport device,
+  // including exterior-mounted racks and interior storage areas.
+  // A value of 0 indicates no cyclist positions are currently available.
+  // Absence of this field indicates cyclist position data is not available
+  // for this vehicle.
+  // If multi_carriage_details is populated with per-carriage
+  // cyclist_positions_available, then this field should describe the entire
+  // vehicle with all carriages considered.
+  // This field is still experimental, and subject to change. It may be
+  // formally adopted in the future.
+  optional uint32 cyclist_positions_available = 12;
+
+  // Experimental: The total number of cyclist positions (rack spaces,
+  // interior hooks, or designated storage areas) on or in this vehicle.
+  // This represents the maximum capacity for bicycles, regardless of
+  // current availability.
+  // A value of 0 indicates the vehicle has no cyclist positions.
+  // Absence of this field indicates total cyclist position data is not
+  // available for this vehicle.
+  // If multi_carriage_details is populated with per-carriage
+  // total_cyclist_positions, then this field should describe the entire
+  // vehicle with all carriages considered.
+  // This field is still experimental, and subject to change. It may be
+  // formally adopted in the future.
+  optional uint32 total_cyclist_positions = 13;
+
   // The extensions namespace allows 3rd-party developers to extend the
   // GTFS Realtime Specification in order to add and evaluate new features and
   // modifications to the spec.
diff --git a/gtfs-realtime/spec/en/reference.md b/gtfs-realtime/spec/en/reference.md
index 2374995f..c35830ca 100644
--- a/gtfs-realtime/spec/en/reference.md
+++ b/gtfs-realtime/spec/en/reference.md
@@ -287,6 +287,8 @@ Realtime positioning information for a given vehicle.
 | **occupancy_status** | [OccupancyStatus](#enum-occupancystatus) | _Optional_ | One | The state of passenger occupancy for the vehicle or carriage. If multi_carriage_details is populated with per-carriage OccupancyStatus, then this field should describe the entire vehicle with all carriages accepting passengers considered.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future.|
 | **occupancy_percentage** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | A percentage value indicating the degree of passenger occupancy in the vehicle. The value 100 should represent the total maximum occupancy the vehicle was designed for, including both seating and standing capacity, and current operating regulations allow. The value may exceed 100 if there are more passengers than the maximum designed capacity. The precision of occupancy_percentage should be low enough that individual passengers cannot be tracked boarding or alighting the vehicle. If multi_carriage_details is populated with per-carriage occupancy_percentage, then this field should describe the entire vehicle with all carriages accepting passengers considered.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
 | **multi_carriage_details** | [CarriageDetails](#message-CarriageDetails) | Optional | Many | Details of the multiple carriages of this given vehicle. The first occurrence represents the first carriage of the vehicle, **given the current direction of travel**. The number of occurrences of the multi_carriage_details field represents the number of carriages of the vehicle. It also includes non boardable carriages, like engines, maintenance carriages, etc… as they provide valuable information to passengers about where to stand on a platform.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
+| **cyclist_positions_available** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | The number of cyclist positions currently available on or in this vehicle. Cyclist positions are designated locations where cyclists can secure their bicycle or similar personal transport device, including exterior-mounted racks and interior storage areas. A value of 0 indicates no cyclist positions are currently available. Absence of this field indicates cyclist position data is not available for this vehicle. If `multi_carriage_details` is populated with per-carriage `cyclist_positions_available`, then this field should describe the entire vehicle with all carriages considered.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
+| **total_cyclist_positions** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | The total number of cyclist positions (rack spaces, interior hooks, or designated storage areas) on or in this vehicle. This represents the maximum capacity for bicycles, regardless of current availability. A value of 0 indicates the vehicle has no cyclist positions. Absence of this field indicates total cyclist position data is not available for this vehicle. If `multi_carriage_details` is populated with per-carriage `total_cyclist_positions`, then this field should describe the entire vehicle with all carriages considered.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
 
 
 ## _enum_ VehicleStopStatus
@@ -353,6 +355,8 @@ Carriage specific details, used for vehicles composed of several carriages.
 | **occupancy_status** | [OccupancyStatus](#enum-occupancystatus) | Optional | One | Occupancy status for this given carriage, in this vehicle. Default is set to `NO_DATA_AVAILABLE`.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future.|
 | **occupancy_percentage** | [int32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | Occupancy percentage for this given carriage, in this vehicle. Follows the same rules as "VehiclePosition.occupancy_percentage". Use -1 in case data is not available for this given carriage.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
 | **carriage_sequence** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Required | One | Identifies the order of this carriage with respect to the other carriages in the vehicle's list of CarriageStatus. The first carriage in the direction of travel must have a value of 1. The second value corresponds to the second carriage in the direction of travel and must have a value of 2, and so forth. For example, the first carriage in the direction of travel has a value of 1. If the second carriage in the direction of travel has a value of 3, consumers will discard data for all carriages (i.e., the multi_carriage_details field). Carriages without data must be represented with a valid carriage_sequence number and the fields without data should be omitted (alternately, those fields could also be included and set to the "no data" values). <br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
+| **cyclist_positions_available** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | The number of cyclist positions currently available on this specific carriage. Cyclist positions are designated locations where cyclists can secure their bicycle or similar personal transport device. A value of 0 indicates no cyclist positions are currently available on this carriage. Absence of this field indicates cyclist position data is not available for this carriage.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
+| **total_cyclist_positions** | [uint32](https://protobuf.dev/programming-guides/proto2/#scalar) | Optional | One | The total number of cyclist positions (rack spaces, interior hooks, or designated storage areas) on this specific carriage. This represents the maximum capacity for bicycles on this carriage, regardless of current availability. A value of 0 indicates this carriage has no cyclist positions. Absence of this field indicates total cyclist position data is not available for this carriage.<br><br>**Caution:** this field is still **experimental**, and subject to change. It may be formally adopted in the future. |
 
 ## _message_ Alert