does it have any safety feature installed?
Yes, They have higher speed limits and lower limits,  lower in areas where they traverse significantly hazardous areas.
Interstate Highway System

In some areas, speed limits on Interstates can be significantly lower in areas where they traverse significantly hazardous areas. The maximum speed limit on I-90 is in downtown Cleveland because of two sharp curves with a suggested limit of in a heavily congested area; I-70 through Wheeling, West Virginia, has a maximum speed limit of through the Wheeling Tunnel and most of downtown Wheeling; and I-68 has a maximum speed limit of through Cumberland, Maryland, because of multiple hazards including sharp curves and narrow lanes through the city. In some locations, low speed limits are the result of lawsuits and resident demands; after holding up the completion of I-35E in St. Paul, Minnesota, for nearly 30 years in the courts, residents along the stretch of the freeway from the southern city limit to downtown successfully lobbied for a speed limit in addition to a prohibition on any vehicle weighing more than gross vehicle weight. I-93 in Franconia Notch State Park in northern New Hamps
how far is carlisle pennsylvania from my location UNANSWERABLE what is the main topic about? The Pennsylvania Turnpike is an east–west toll highway. which route does it connect to? Begins at the Ohio state and ends at the New Jersey. does the first place mentioned experience any seismic activities? It has registered more than 200 earthquakes with a magnitude of 2.0 or higher have occurred since 1776. what are the people native to this place? Many of these Ohio-country nations were multi-ethnic  and sometimes multi-linguistic. when was the aforementioned toll highway commissioned? During the 1930s. and was there a reason for it being different? It was one of the earlier long-distance limited-access highways in the United States, and served as a precedent for additional limited-access toll roads and the Interstate Highway System. describe the system mentioned above? It is a network of controlled-access highways that forms part of the National Highway System in the United States. define standards for this kind of access highways? Controlled access roads, few exceptions, traffic lights are limited to toll booths and ramp meters, metered flow control for lane merging during rush hour. does it have any different techniques used for it's construction? Yes, contracts under the new program. The first contract signed was for upgrading a section of Interstate 44 and also marked its portion of I-70 as the first project in the United States completed under the provisions of the new Federal-Aid Highway Act of 1956. did it have any history of accidents? UNANSWERABLE
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Interstate Highway System [SEP] Speed limits
Being freeways, Interstate Highways usually have the highest speed limits in a given area. Speed limits are determined by individual states. From 1974 to 1986, the maximum speed limit on any highway in the United States was , in accordance with federal law. Typically, lower limits are established in Northeastern and coastal states, while higher speed limits are established in inland states west of the Mississippi River. For example, the maximum speed limit is in northern Maine, varies between from southern Maine to New Jersey, and is in New York City and the District of Columbia. Currently, rural speed limits elsewhere generally range from .