Driving in Kota Kinabalu is according to the British system, steering wheel on the right, drive on the left, markings are in kilometers. Speed limits are mostly 50 km/h in residential areas and 100 km/h on the highways.

Road signs follow the international standards. The roads are fairly straight forward and difficult to get very lost on. You can buy a decent map from any stationary store (and some bigger petrol stations), or pick up a touristy, not-to-scale map from the hotel you are staying at.  

Taxis
If you're going to go mostly to the city centre for some shopping, to enjoy the night life and visit a few other tourist attractions and perhaps a few organised tours, you really don't need to rent a car, in fact, you will have less hassle if you don't. 

Taxis are plentiful and run at all hours, you can flag them down anywhere it is legal for them to stop.  They also congregate around busy areas like hotels, shopping centres and the harbour area. They are usually Toyota Crowns or Protons sedans with sufficient luggage space.  They used to be white on red (older ones still are), but you see ever more solid red one, blue ones and even yellow ones.  But, details like the driver's address and contact numbers and permit number on the door is a legal requirement, and they always have the sign on the door that says: "Teksi Bermeter" or "metered taxi" event though that is not strictly true now (see below).

Legally, taxis can only carry 4 passengers (1 in front and 3 in the back) and are fined if they are caught carrying more, so don't bother begging for your party of 5 to be taken in one taxi (small children are the exception). They are all air conditioned.

Taxi's have meters, but, did I find out today, they have been declared defunct.. The JPJ, who is responsible for taxi regulation, have estabalished a distance chart.  Thus rates are fixed. Just ask "how much" as you get in. From town, destinations like the Sutera Harbour and the STAR hotels, rates are usually fixed at around RM10 and RM15 respectively.  Between midnight and 6am, taxis are more expensive and you can usually expect to pay the meter (or normal price) plus 50%.

Rental Cars
Taxis are cheap, but if you are staying longer than just the usual holiday, they quickly add up. Renting a car might therefore become a viable option. 

There are many types of rentals to choose from.  From the exceptionally fuel efficient, but oh-so-small Kancil on the one end of the scale, right up to the petrol guzzling, 4x4 Toyota Land Cruiser (or similar) on the other end.

To rent, you have to be over 23 years of age and have had your license for a minimum of two years.  A security deposit, usually in the shape of a credit card imprint and copies of passport, is a prerequisite for the rental.  For the rest, procedure is according to international standards. 

Parking
Finding parking in the city is a bit challenging, but you have to know where to look. There are big parking arcades in the Centre Point (usually always has parking on the 5th floor), Wisma Merdeka as well as two levels in the basement of Wawasan Plaza. They cover the two extremes and the centre of the CBD and parking in either the Centrepoint or Wisma Merdeka, will put you within walking distance of pretty much everything within in the city centre. There is another shopping centre and parking arcade at Karamunsing, but as it's a little removed from the city centre, parking there is handy for that complex only, and the parking there is usually quite full.

Throughout the city people are constantly coming and going, so even when there is no parking, cruising in circles for a few minutes will eventually uncover an opening. At night, it's not too crowded, except around the popular hangouts like the Waterfront and around Shenanigans and the Hyatt.

Parking arcades and controlled access points like in front of the Hyatt and at The Waterfront, works on a ticket system. The parking arcades usually requires RM2 paid on entrance which includes 2 hours (I could be wrong, check the board or ask), the difference is collected when you return the ticket at the end of your stay.  The Hyatt and the Waterfront also uses tickets, but collects the whole kitty when you exit. Everywhere else you park you will see (or sometimes you won't see them) parking attendants covered in gloves, sunshades and head dressing that cover their entire heads. They manually write out tickets that gets placed underneath your wiper after 5 minutes. 

Before you leave, you have to take this ticket and find the said attendant and settle your account - usually less then RM1, depending on how long you parked.  Failing to find the attendant, you can locate a little wooden hut that will be somewhere in the vicinity, which is their local 'office'.  Failing that, you could always pay next time you park anywhere else in the area, but might pay a little extra per day for every day you delay.

Road Safety
Road safety is relative. The Sabahans are not really aggressive drivers, although the big SUV drivers like to tailgate and intimidate. In general, expect anything and do your best in defensive driving, because drivers don't always indicate and like to float in and out of lanes.

With construction on bridges, that will hopefully make life easier, in progress, traffic is still a bit of a mess during peak periods in the morning and the evenings and Saturday and Sunday mornings, but otherwise the traffic is tolerable.

Road quality is relatively good, except on the back roads and far flung rural areas. Many roads don't have restrictions for heavy trucks (none which are strictly adhered to anyway) which cart around mostly heavy loads of timber and construction materials, so with frequent down-pours and pounding by these heavy vehicles, pot holes are not uncommon.

Take care, especially on unfamiliar roads in pouring rain. Should you get caught in a downpour, often a challenge for wipers, don't hesitate to switch on your hazards and find the side of the road to wait it out (not too far in though, beware the open, uncovered monsoon drains). Also beware pools of water that form on the road during heavy downpours. But after the rain, they quickly drain away.

Law Enforcement
Traffic Officers are often seen, but usually in their capacity of directing traffic.  They are indiscernible from the Police, also wearing dark blue uniforms and riding mopeds or motorbikes branded with white and dark blue.

I have never come across a speed trap either in the form of a camera or a radar device.  However, roadblocks do occur, especially during blitz-season when most road tax tags expire. Make sure your road tax is up to date. It's a sticker with a 3D hologram on the driver side and the date printed is when the tax expires.

Always carry your driver's license. Don't drink and drive.

Fuel is relatively cheap with many service stations dotted about, and if you rent one of the small cars like a Kancil or a Kellisa, you'll drive forever on one tank.