Unlike air travel, where strict 3-1-1 rules limit liquids in carry-on bags to 3.4 ounces, trains generally allow you to bring any volume of liquid on board. In the United Kingdom, Europe, and North America, there are no specific restrictions on the amount of water, soda, or juice you can carry in your luggage or by hand. This flexibility extends to toiletries such as full-sized shampoo bottles and perfumes. However, there are some regional nuances regarding alcohol. For instance, Eurostar allows a reasonable amount for personal consumption, while some US Amtrak routes may restrict drinking your own alcohol to private sleeper cars rather than public coaches. Additionally, for safety, flammable or hazardous liquids are strictly prohibited on all rail networks. Because you don't have to navigate liquid-specific security scanners, train travel remains one of the most convenient modes of transport for those who prefer to travel with their own beverages or larger cosmetic products without the hassle of decanting them into travel-sized containers.