A taxicab operator not already engaged shall not refuse or neglect to convey any person applying for service to any place within the City. The person first applying for service shall have the immediate and exclusive use of such taxicab to his destination, unless the passenger is requested and consents to the carrying of additional passengers. A passenger shall be driven by the most direct and safe route to his or her destination. This section shall not be construed to require any taxicab driver to take as a passenger any person under the influence of liquor or narcotic drugs, or justify his assenting to the carrying of liquor in violation of any law or ordinance, or to the use of his taxicab for immoral or illegal purposes or contrary to any provision of this chapter.