Paris has an excellent underground train system, known as the Métro (short for Chemin de Fer Métropolitain i.e. Metropolitan Railways). Although you will probably take the RER subway train from the airport to Paris, don't be confused: RER isn't the name for "French subway train", and only a few large stations service the RER network of trains. You'll want to look for the Métro stations, marked with a large "M" sign.
There are 16 Métro lines (lignes) (1-14, 3bis and 7bis) on which trains travel all day at intervals of a few minutes between 5 AM and 12:30AM (Saturday night/Sunday morning: 01:30), stopping at all stations on the line. Times for trains can be seen on an electronic scrollboard above the platform. Line 14, which is fully automated, is called the Méteor. Scheduled times for first and last trains are posted in each station on the center sign.
The lines are named according to the names of their terminal stations (those at the end of the line). If you ask the locals about directions they will answer something like : take line number n toward "end station 1", change at "station", take the line nn toward "end station 2" etc. The lines are also color-coded.
In addition there are 5 train lines called RER A, B, C, D, E. RER trains run at intervals of about 6 - 7 minutes, and stop at every station within Paris. Although a regular subway ticket can be used within Paris (Zone 1), it is necessary to pass the ticket through the turnstile when passing between the subway and the RER lines, as the two systems are separate networks. This ticket is necessary to both enter and exit the RER networks, as the RER trains travel on to the Parisian suburbs, outside the zone where a regular subway ticket can be used. Beware that traveling outside the city center without a valid RER ticket will get you fined, and the packs of inspectors who roam the system show no mercy to tourists pleading ignorance. In particular, CDG airport is not within the city, and you'll need to purchase a more expensive RER ticket to get there (see Get in).
For travel outside of the Paris zone, the train arrival times are shown on a monitor hanging from the ceiling inside the RER station above the platform. Information about the stops to be made by the next train is presented on a separate board also hanging from the ceiling. It is important to check this board before boarding the train, as not all trains make stops at all stations on a given line.
RATP is responsible for public transport including metro, buses, and some of the high speed inter-urban trains (RER). The rest of the RER is operated by SNCF. However, both companies take the same tickets, so the difference is of little interest for most people except in case of strikes (because RATP may strike while SNCF does not, or the other way round). Current fares can be found at their website. Basically, as you move further from Paris (ie into higher zones), tickets get more expensive.
For the subway, a single ticket (ticket t+) costs €1.50; however, it is generally not advisable to buy tickets by the unit and to rather purchase a carnet of ten tickets, which can be bought for €11.10 at any station, that will bring the price per ticket down to €1.11. Tickets, named 'Tarif Reduit' may be purchased for children under the age of 10 for €0,55 each, or a carnet for €5,50. Both tickets are valid for unlimited metro, RER, bus and tram transfers during one hour. Tickets do not expire.
A 1-day ticket, a weekly pass, and a monthly pass are also available. The price varies according to the zones for which the ticket can be used. The cheapest 1-day ticket called Mobilis, is valid for zones 1-2, with a price of 5.60 euros. Once bought, it is necessary to write in the spaces provided on the ticket: 1) the date the ticket is being used in European notation of day/month/year (Valable le), 2) the last name (Nom), and 3) and the first name (Prénom). Unfortunately, this ticket is not valid for use for travel to/from Charles de Gaulle airport.
If you're staying a bit longer, the weekly and monthly passes are called Carte Orange (1 week pass, €16.30 for Paris and inner suburbs), and the monthly Carte Orange Mensuelle (1 month pass). Note that an Hebdomadaire (eb-DOH-ma-DAYR) starts on Mondays and a Mensuelle on the first of the month. The Carte Orange is non-transferrable, and therefore requires the user to provide information on the pass after the sale. Since 2008, the Carte Orange is sold as refill of a "Navigo Decouverte" no contact pass. This pass is sold for 5€. You must write your last name (nom), your first name (prénom) and stick your photo on the nominative card. After, you have to refill your pass with a Carte Orange Hebdomadaire (1 week pass), or a Carte Orange Mensuelle (1 month pass). You have to choose at least two of the contiguous "zones" : Paris is first the zone 1, La Défense is in the third zone, Versailles in the fourth,... Everything related to a "Navigo" pass is in purple (eg. the target for the pass in the turnstiles).
Although not as good a deal for adults in most cases as the Mobilis or Carte Orange, there are also 1 to 5 day tourist passes, called Paris Visite available, which are a bargain for kids of ages 4 to 11, starting at €4.25 per day for travel within zones 1-3.
Keep your métro ticket or pass with you at all times, you may be checked or "controlled". You will be cited and forced to pay on the spot. Although the most likely spots for controls are at big métro stations or during métro line change "correspondences", it is not uncommon for "controleurs" to check tickets on trains. RATP agents may be present in the metro stations even on Sunday night.
Métro stations have both ticket windows and automatic vending machines. The majority of automatic vending machines take only coins or European credit cards with a pin-encoded chip on the front. Therefore, to use either Euro bills or a non-European credit card with a magnetic stripe, it is necessary to make the purchase from the ticket window.
If you have any tickets or Carte Orange for zone 1-2 ("inside" Paris area: the lower rate) and want go to La Defense from Chatelet, you have to take the metro (line 1). You can take the RER A (and save a few minutes) but you have to pay an additional fare, because even though you arrive at the same station, the RER exit is supposed to be outside of Paris! On the other hand, métro fares are the same, even in the suburbs. So be careful, there are usually a lot of ticket examiners present when you get off the RER A.
Each station displays a detailed map of the surrounding area with a street list and the location of buildings (monuments, schools, places of worship etc) as well as exits for that particular metro. Maps are located on the platform if the station has several exits or near the exit if there is only one.
When the train arrives, the doors may not open automatically. In such a case, there are handles located both inside and outside the train which you have to push, or unlatch in order to open the door.
An Overview of Wines in Spain, 1882
9 months ago