Do not consider the installation of ramp metering (unless appropriate mitigating measures can also be implemented) at locations where:
The adjacent local street network will be negatively impacted either from motorist diversion or ramp spillback because streets are geometrically deficient or already operating at or close to capacity
THE first metered ramp was installed in Chicago on the Eisenhower Expressway in 1963. This first application, however, was preceded by successful tests of the effectiveness of metering traffic entering New York tunnels and ramp closure studies in Detroit.
It is interesting to note that the initial Chicago study featured a police officer, stationed on the entrance ramp, who stopped traffic and released vehicles one at a time at a rate determined from a pilot detection program