Many people argue that police officers use loitering laws to clear neighborhoods of "undesirables²." Some courts have held loitering laws to be unconstitutional （不合宪的，违宪的）on the grounds that they are enforced discriminatorily（歧视地） against poor persons and ethnic³ minorities（少数民族） and that they unduly⁴ restrict people's rights to travel on public streets. However, the safest place to challenge the validity （有效性、合法性）of a loitering law is in the courts, not on the streets to a police officer's face.

　　5. An Officer Who Pulled Me Over for a Traffic Offense⁵（交通违章） Said That I'd Be Arrested if I Didn't Supply Identification. Is This Legal?

　　Yes. Traffic offenses⁶ such as speeding（超速） and unsafe lane changes are generally classified as "infractions（违章）," for which drivers are given citations⁷ in lieu of arrest. However, an officer has the right to demand personal identification—usually a driver's license⁸ and the vehicle registration⁹. A driver's refusal to supply the information elevates the situation to a more serious offense, for which the driver usually can be arrested. The simple refusal to answer questions is not a crime, but the refusal to supply identification, combined with the suspected commission of a traffic offense, is.

　　6. An Officer Pulled Me Over for Suspicion of Drunk Driving （酒后驾车）and Questioned Me About Where I'd Been and What I'd Had to Drink. Can I Be Arrested for Refusing to Answer These Questions?

　　No. An officer has the right to conduct a field sobriety test of a suspected drunk driver. But the driver has the right to refuse to answer questions. In such a situation, the validity of an arrest would depend solely¹⁰ on the person's driving pattern and performance on the field sobriety tests. （See Chapter 24 for more on drunk driving and field sobriety tests.）

　　本节的问题：　　field sobriety test 什么意思？
　　答案：　　现场清醒度测试/现场酒精测试