After 8 to 12 days, on average, symptoms of measles can begin. The period between measles transmission and the start of symptoms is called the incubation period.
Driving Laws In Greater Philadelphia. The maximum speed limit in Pennsylvania is 55 miles per hour unless posted otherwise. The maximum speed limit on interstate highways is posted after each interchange; on other highways the maximum speed limit is posted at approximately half-mile intervals.
A Reduced School Speed Limit Ahead (S4-5, S4-5a) sign is normally used to inform road users of a school zone speed limit where the speed limit is 10 mph (15 km/h) or more below the speed limit on the approach road, or where engineering judgment indicates that advance notice is appropriate.