No. 1
M: I'd like to go to City Hall. How long will it take to get there?
F: About 40 minutes. If you're in a hurry, you had better take a taxi. [40 minutes by what means? Your dialogue requires this to be understood.]
M: Maybe I should/will. Thanks a lot. ["ought to do so" is correct English but not very likely in everyday conversation]
No. 2
M