1. There's not enough parking space. You turn up at a busy time and you can drive round and round for ages looking for somewhere to dump the car. People abandon their vehicles on double yellow lines, on pavements, wherever.
2. There's very poor provision for wheelchair users. To give just one example: if you come in at the entrance on Broadway, you find a gate has been built across the pavement, forcing wheelchair users into the road. Some internal roads (the hospital is as big as a town centre) have no pavements at all- and where they exist there are too few drop down points.
Whoever designed the hospital and its grounds just wasn't seeing the bigger picture.