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.
If no limit is posted, drive no more than 55 mph (88 km/h). Often, it is common sense to keep your actual speed below the posted limit. For example, the legal limit on a slippery or fogged-in expressway might be 55 mph (88 km/h), or even 65 mph (100 km/h), but the safe speed to drive would be much lower.