The officer can conduct this test without a warrant or permission because society has a right to protect itself from drunk drivers.

Balance between individual rights and law

Explanation:

solution

Drunk driver create risk on road and it may cause other peoples to crash without hitting them

and they can hit oncoming traffic

so so that if police officer see any driver with bad behavior they can test driver to check driver has been drinking alcohol or not

and if he caught then drunk driver vehicle can be permanently disabled

so police conduct this test for balance between individual rights and law