What is the primary danger when an animal-drawn vehicle enters an intersection controlled by traffic lights?

1. The horse will read the traffic lights and change color
2. Due to slow acceleration and travel speeds, animal-drawn carts take significantly longer to clear the intersection width, requiring the driver to enter only on green when there is sufficient time to clear before opposing traffic gets green
3. Traffic lights do not apply to animal-drawn vehicles
4. The cart will accelerate to 60 km/h instantly