911 emergency call system

After AT&T made 911 available in 1968 as the emergency telephone number for the North American Numbering Plan, local governments across the U.S. began its implementation. SRI was a nationally recognized leader in the design, engineering, and analysis of several early implementations. In their reports, SRI engineers predicted correctly that response time by emergency personnel would be reduced with the public’s use of 911 services.

SRI was also first to propose that a tax on telephone lines be used by government to pay for 911 systems—today the accepted means of covering system costs.

By 1979, approximately 800 emergency call systems were in place across the country. Today, virtually every municipality across the U.S. has a 911 system in operation. An estimated 240 million 911 calls are made each year.

Read our 75th anniversary blog feature

75 years of innovation: 911 emergency call system

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