Disadvantages of travelling by air

flying or driving?

It is true that travelling by air has resulted in numerous benefits but there are a number of disadvantages to consider. The most important disadvantage of travelling by air is cost. People always deliberate about cost when they choose a transportation to travel. The cost of the flight tickets is extremely high and also difficult to buy in some special occasions. For example, in New Year's Eve, the demand of travelling increases astonishingly so the flight tickets will be expensive and sold out immediately. Another additional disadvantage stems from bad weather as well as technical problems or even terrorisms; therefore, these incidents may lead the flight to be at stake. As the result of that, scheduled flights will be postponed or cancelled hourly which is inconvenient for passengers. A delay of a few minutes is not serious but a long delay can force passengers to miss an important engagement. Lastly, it is a thorny problem for people who have airsickness because they are not able to travel by air eventhough they desire to have a flight. In conclusion, I think you should consider cautiously before making a decision to travel.

I think the idea is quite nice, although you could make it more systematic. Before you mention the most important disadvantage, perhaps it'll be better to categorize the advantages and disadvantages, then continued by explaining the positives or negatives in details.

Quang, you spelled "even though" as one word when it should have been spelled as two words, separated by a space to indicate 2 words of connected meaning. You should have also used a comma because of the conjunction in the presentation of; "... minutes is not serious , but a long delay can force passengers..." Remember use a comma to connect 2 different topics of relevant discussion in a single sentence. There are also instances when you should have considered using verbs instead of nouns such as in the case of the following:

... before making a decision to travel....
- ... before DECIDING to travel...

... benefits but there are a number of disadvantages...
- ... but there are SEVERAL disadvantages...

Since you did not specify if this was supposed to be for an IELTS test or just an English writing exercise, I decided to review your work using US English. These are the corrections specific to that type of English language.

Really thank you for helping me correct my mistakes.
By the way, this paragraph is just an writing exercise that I practise to reach IELTS test in the future :D
I'll try to rewrite this carefully.