Some useless data I acquired with Chat GPT...
Let's assume that in the game Road Fighter, the car can run at a maximum speed of 2 screens per second, which is 384 pixels.
We don't have the size of the player's car, but let's also assume that the car in the game was inspired by several sports cars from the 80s, such as those listed below:
Ferrari Testarossa - 4.50m
Lamborghini Countach - 4.14m
Porsche 911 - 4.49m
Mazda RX-7 - 4.26m
Toyota Supra - 4.38m
Nissan 300ZX - 4.52m
Honda NSX - 4.44m
Chevrolet Corvette - 4.49m
On average, we can say that the player's car is 4.43m long. This means that the 384 pixels it covers in one second correspond to 114.69m per second.
Converting to km/h, in Road Fighter, the maximum speed is 384.91 km/h. If you decide to capture video footage from the game for an accurate speed calculation, feel free to send me the data. 
