Sydney trains play two recorded announcements repeatedly.
The first is: “Help us avoid delays. If you feel unwell, don’t risk staying on the train. Staff at the next station can get you help”. Linguistically, the most interesting thing about this is the consonant clusters – /kstst/ in ‘next station’ (which I wrote about with regard to ‘next stop’ here) and /skst/ in ‘risk staying’. In informal speech, the second can be reduced to /kst/ – approximately ‘nekstop’ or ‘nekstation’, but the first can’t.
The second is: “Please keep your personal belongings with you at all times. If you see unattended baggage, please do not touch it, but notify staff immediately. Thank you.”
The first announcement contracts ‘do not’ to ‘don’t’, but the second doesn’t. The contracted form is usual and natural and the uncontracted form either formal or (in this case) emphatic (as well as being uncontracted, they are spoken more strongly). The first announcement and the ‘next stop’ announcements are made by a female voice, and the second and “Stand clear, doors closing” by a male. Female = caring advice and information; Male = authority and warning???? The authority of the second announcement is not softened by the use of ‘please’ and ‘thank you’.