Public Transport

Unless you are a glutton for punishment, don't hire a car and try to drive around inner London. It's too busy, too expensive and too difficult to find your way around, get parking etc., unless you are a local or have the knowledge of a local. London is that sort of place. If you intend to hire a car and visit others parts of Britain after your visit to London, get yourself a Visitors Oyster Card and do all your travelling in and around London using it, and leave picking up a hire car until after London.
An Oyster Card, which is London's version of the cashless travel ticket, lets you travel on above ground trains, underground trains and buses so there isn't a corner of London that you might choose to visit that your Oyster Card can't take you there. The pre-paid cards come with some credit included. You tap on at the beginning of every journey and tap off at the end, and the cost of travel is automatically deducted from your credit. A visitors Oyster Card has a fixed maximum charge per day if your first journey of the day begins outside of the morning peak period.
Oyster Card: Visitors Guide
Riding The Underground
The inner city area, where most of the city's major attractions are, has a maze of underground railway lines and stations, and the underground - referred to locally as The Tube - is the best way to get around. It is quick, efficient and everybody uses it, so it's often very crowded. Before you go anywhere in London, it is wisdom to plan your trip first. Chances are you will need to travel on more than one line, so you'll need to know in advance which station to get off at, and which line your next train travels on and in which direction. It all sounds very complicated and a bit daunting if you've never done it before, but provided you take the time to plan, it is really quite simple and very efficient. All lines are named and colour-coded so all you have to do when changing trains is look for the exit marked with the name and colour of the line you want. When you reach the next line, check to see if the station you want is "up" or "down" the line and head for the appropriate platform. If you feel the need to brace yourself before boarding a train, or find you are on the wrong platform or train, don't worry, trains come and go every few minutes so you'll soon be on your way.
London Underground Map
The platforms, escalators and connecting tunnels at underground stations are full of people in motion at most times of the day and night, so be prepared to go with the flow. Avoid taking large bags on the Tube; not all stations have elevators, and if you end up having to haul suitcases up and down escalators, it is very easy to inerrupt the traffic flow. If you have no choice and find yourself struggling with your luggage, which has happened to us on a number of occasions, the locals in the main are very understanding and on numerous occasions people have rushed to our aid if they saw we needed help. There are usually plenty of station staff around - they won't help with the luggage but will point you to whichever platform you need or the station's exit if you are unsure. When travelling on escalators or walking along passageways, keep to the right to allow passenger who are in a hurry to pass you on your left side.

Riding The Thames Clipper
London has frequent river boat services on the Thames known as Thames Clippers. These run up to every 20 minutes between Embankment Pier and North Greenwich Pier. The Woolwich Ferry, with 2.5 million passengers every year, is a frequent service linking the North and South Circular Roads. Other operators run both commuter and tourist boat services in London.

Picking up a hire car
If you are going to hire a car after visiting London, think very carefully about going back to the airport and picking up your hire car from there. It is the obvious place to do this - there are plenty of companies based at the airport with a myriad of options, and it is on the outskirts of the city so you don't have to battle inner city traffic - but it has its traps for the unwary traveller and can end up costing you dearly. Don't think that because you have used a certain hire car company at home and found them trustworhty, you will have the same experience there. You might ... but you might not. Hire car companies pay a lot of money to have both a sales point in a terminal at an airport like Heathrow, and for space to park their hundreds of cars there. They have to get that money back from someone and that someone is you. Even though the cost per day to hire a car from a major airport is always higher than hiring the same car from the same rental company in a regional centre, they have ways of getting even more cash out of you.
Even if you have pre-booked a specific size car, don't be surprised if, when you go and pick it up, they'll tell you that car is not available and try to upgrade you to a more expensive one. Another trick they pull is to have a quick chat with you upon arrival before filling in the paperwork. You think they are just being friendly, in fact they are sizing you up for an upgrade by getting a brief picture of how many are travelling, what luggage you have and where you are going. They then tell you that the car you have ordered is not suited to your needs and before you've finished telling them about your trip, they already have a contract filled out for a different car at a much higher rate than you were quoted. They play on the fact that you have just completed a 24 hour flight and the last thing you want to be doing is haggling with a salesperson, and that asking to be taken back to the airport's arrivals hall in their courtesy bus so you can check out what other car hire companies have to offer is something you probably wouldn't even think of with them standing over you pushing for your signature.
One way to reduce your chances of getting taken for a ride (no pun intended) is to hire a car in a regional city away from an international airport. Rather than catch a train from your accommodation to Heathrow, catch one to a regional city in an area you are going to explore by road instead. It could be Leeds if you plan to visit Yorkshire; Southampton or Portsmouth if you are heading for the south coast; Edinburgh or Glasgow (the cheapest of the two) if you are touring Scotland; Nottingham, Cambridge, anywhere but Heathrow! It will cost a few pounds to get there by train from London, as well as the cost to get back to Heathrow before you fly home (unless you pay a premium to return the hire car to Heathrow) but you will save money and avoid the feeling of having been conned spoil your holiday which it did for us the first time we hired a car at Heathrow. I had to fight long and hard for months after returning home, having been lied to about the size and economy of the car they forced me to upgrade to. I did eventually get some money refunded, but only after relatives in Britain threatened to take legal action on my behalf. The argument they used all the way through was that if I didn't agree to it, I shouldn't have signed the contract.
We have heard of this happening to many people and with different hire car companies so there would be no point in naming and shaming the company we used as many use that ploy. No doubt if you stand your ground at the check-in counter you will probably get what you want in the end, but for me, I never want to place myself in a position where that could happen again, nor would I wish that experience on anybody.
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