In order for a vehicle to have any meaning, it must move - otherwise it's not a vehicle.
Faster speeds mean more (time) efficiencies, obviously.
It also means larger stopping distance, higher risk of losing control (like in a turn), less time to react and stop. Also, above around 30-40 km/h, energy efficiency is close to inversely proportional to speed, ie you have half the range at 80 km/h as you have at 40 km/h
Somewhere in between lies a compromise of efficiency and safety. There is no way you can determine a "safe" or "optimum" speed, it's a political and regulatory "made up" speed.
Safer roads mean higher speeds can be sufficiently safe, regarding other traffic, intersections, overview and many more factors. Driver skills and morale, as well as vehicle passive and active safety also plays a very important role.
So now it seems HK TD is upgrading their cams to the UK style where two photos are taken over a known distance, and the time compared for average speed, reading the license plates of all cars passing. It should be a safer system as it prevents the "stop-and-go" by each speed cam, which just makes it even more dangerous (and wastes energy by all that braking and acceleration).
If Hong Kong were really serious about traffic safety, they should get onto a few tasks:
1) Improve the road signs, both for clarity and have them early enough
2) Issue fines to drivers who don't drive left after they are done passing
3) Issue fines for not using the turn signal. I find that it is only about 5% to 10% of drivers who cares about showing their intended intentions.
4) Adjust the speed limits to be more realistic. The more realistic speed limits are, the more people are likely to adhere to them
5) Make it mandatory for trucks and buses to have speed limiters installed, like it exists in most civilised countries now.
1)
Having driven only around 3,000 km in HK now, I find it one of the most difficult places to navigate. I have driven in many different countries, both LHD and RHD cars (mainly LHD). Few places have I experience such amateurish signage, on par with developing countries like ... no need to mention any, I will just offend some people, but I am sure you know what I mean. "Follow the road for 10 km" - well, good luck with THAT, some times what looks like an exit turns out to be the main road. Other times, two or three lanes just split up with no notice (or confusing directions to parts of town only well oriented drives all know of). Double white lines then prevent you from getting in the lane you need to. Duh.
Sign are meant to inform those that don't know already. Those that already know where to go don't need the signs anyway. Two lanes, one become a turning lane only at the latest moment, and you only know it if you have been there before, as the arrows painted on the road are so close to the intersection they are only useful to tell you "you are now in the wrong lane" - when it is too late. The other lane, going straight, is now full of traffic. Good luck to squeeze in, or follow the turn and then navigate back to where you wanted to go. This is such a huge threat to traffic safety, it doesn't matter what speed you are at.
HK TD: Please improve your traffic signs, to reduce those traffic accidents where people cause accidents out of despair of navigating your complicated and very poorly signed roads.
2)
HK taxis might go fast, but their acceleration aren't too good with those lazy LPG engines. Even going uphill, so many of them insist on the right lane on the expressways, even when they are 30 km/h below the limit. For all those lanes, it's a waste of expensive HK land, when they aren't utilised properly. Send a group of officials to Germany and try the highway for a few days (with a local experienced driver to show them how).
3)
So many dangerous situations because people just don't give a d... about showing their intentions. Suddenly turning, or maybe you get stuck because the car in front of you stops dead - oh, he has to turn? Well thank you for NOT letting me know.
4)
Tuen Mun Castle Peak road - a lot of it is 70 km/h, despite roundabouts, road construction, traffic lights, bikes ... parallel to it is the Tuen Mun expressway - 5 lanes at times, and 70 km/h speed limit as well. Where the h... is the f...... logic to THAT? People so focused on keeping the speed limit within the narrow band they have less time to look out and drive sensibly, use the turn signal, adjust to surroundings.
5)
Going the normal speed limit, or as 70% of drivers or so, +10 km/h, you get passed by these huge trucks at 120 km/h. Before I had a car I dared my life on a bike in HK, but eventually gave up. Those trucks and mini buses especially, just drive like there was no tomorrow. Not just about speed, but also lack of looking out where they are going, who else is there. Right of way, turn signals, giving you space for your bike. A former neighbor of mine got hit by a truck and was crippled, lost his job and all. That wasn't about speed itself, but about recklessness, and inability to "drive according to conditions"
Having at times ridiculously low speed limits and a big brother camera system doesn't make it alone in road safety. OK, then, why not make the speed limit 10 km/h all over Hong Kong, that would suit the argument about "slower is safer". It's all a compromise, but should be an educated one, not as silly as it is now.
Serious about safety? Open eyes and find there are many more parameters than speed only.
