Step 1
Objects: a bus, a car(1), a car(2), a two-way street

Step 2
General Objects: a bus, a car(1), a car(2), a two-way street
Text in the Image: N/A
Objects that specifically refer to the Proper Noun of the Real World: N/A

Step 3
triplets: [a bus, General Objects, is on, a two-way street, General Objects]
[a car(1), General Objects, is on, a two-way street, General Objects]
[a car(2), General Objects, is on, a two-way street, General Objects]

Step 4
(1) Node with max degree: a two-way street.
(2) Location of a two-way street: [Spanning horizontally across the middle of the canvas].
(3) Location of a bus, a car(1), a car(2): 
a bus: [Center of the two-way street];
a car(1): [Left side of the two-way street];
a car(2): [Right side of the two-way street].

Step 5
Bounding Boxes of the Objects:
a bus, General Objects: [0.300, 0.400, 0.700, 0.600] - Positioned centrally on the two-way street.
a car(1), General Objects: [0.100, 0.400, 0.300, 0.600] - Positioned on the left side of the two-way street.
a car(2), General Objects: [0.700, 0.400, 0.900, 0.600] - Positioned on the right side of the two-way street.
a two-way street, General Objects: [0.000, 0.350, 1.000, 0.650] - The street spans horizontally across the middle of the canvas.

Step 6
{
  "Bus": {"phrase": "a bus", "coordinates": [0.300, 0.400, 0.700, 0.600]},
  "Car1": {"phrase": "a car", "coordinates": [0.100, 0.400, 0.300, 0.600]},
  "Car2": {"phrase": "a car", "coordinates": [0.700, 0.400, 0.900, 0.600]},
  "Two-way Street": {"phrase": "a two-way street", "coordinates": [0.000, 0.350, 1.000, 0.650]}
}