diff --git a/gtfs/spec/en/reference.md b/gtfs/spec/en/reference.md
index f4a21be3..a451f52f 100644
--- a/gtfs/spec/en/reference.md
+++ b/gtfs/spec/en/reference.md
@@ -263,6 +263,7 @@ Primary key (`trip_id`)
| `shape_id` | Foreign ID referencing `shapes.shape_id` | **Conditionally Required** | Identifies a geospatial shape describing the vehicle travel path for a trip.
Conditionally Required:
- **Required** if the trip has a continuous pickup or drop-off behavior defined either in [routes.txt](#routestxt) or in [stop_times.txt](#stop_timestxt).
- Optional otherwise. |
| `wheelchair_accessible` | Enum | Optional | Indicates wheelchair accessibility. Valid options are:
`0` or empty - No accessibility information for the trip.
`1` - Vehicle being used on this particular trip can accommodate at least one rider in a wheelchair.
`2` - No riders in wheelchairs can be accommodated on this trip. |
| `bikes_allowed` | Enum | Optional | Indicates whether bikes are allowed. Valid options are:
`0` or empty - No bike information for the trip.
`1` - Vehicle being used on this particular trip can accommodate at least one bicycle.
`2` - No bicycles are allowed on this trip. |
+| `cars_allowed` | Enum | Optional | Indicates whether cars are allowed. Valid options are:
`0` or empty - No car information for the trip.
`1` - Vehicle being used on this particular trip can accommodate at least one car.
`2` - No cars are allowed on this trip. |
#### Example: Blocks and service day