Author Topic: The Poway Grade Tunnel  (Read 8009 times)


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The Poway Grade Tunnel
« on: January 07, 2011, 09:12:47 PM »
When the State Highway System took over the Inland Route on August 15, 1931, the first area of concern was the Poway Grade.  How could the highway be made safer for drivers?  One option was to tunnel under the Poway Grade.   

State surveyors have been at work the past few days, surveying a route for a proposed tunnel to take the place of the long, steep Poway grade. 
State engineers announced at the time that they took over the inland highway that one of the first steps in the improvement of that route would be the elimination of the Poway grade by a tunnel.  It is the plans of the engineers to follow the old Poway grade route for a distance, tunnel through the hill and have the road continue on the south side of the hill to a point near the Murphy Canyon road.  There it will connect with the present inland highway, according to plans.
This means not only that a new route is being selected, but also that there will be about 18 miles of new paving laid. 
(Vista Press, September 17, 1931)

Was this tunnel concept a new idea?  No it was not.  As early as 1908, during the construction of the Inland Route, there were discussions about tunneling under the Poway Grade.

Engineer George Cooke of the highway commission said that surveyors are now at work on the San Diego end of a road to Escondido and that survey and estimates would be made either for a tunnel or cut through the crown of the old Poway grade leading to the new road down Murphy canyon and through Mission Valley.(Los Angeles Herald, July 19, 1908)

By 1932, the highway commission was still contemplating tunneling under the Poway Grade.   

The official statement also calls for seven miles of new route from Poway corners to San Clemente canyon, which would eliminate the present Poway grade.  As previously announced, the highway commission contemplates tunneling through Poway hill. 
(Vista Press, April 21, 1932)

What happened to the Poway Grade tunnel?  Unfortunately, the Vista Press did not report the commission’s final decision.  I checked the Poway Public Library, but there were no newspapers for the 1930s.  I will have to search the San Diego Union Tribune to find further answers.   

On September 14, 1950, the Miramar to Lake Hodges stretch of the realigned Highway 395 was officially opened.  The Poway Grade was finally by-passed.  In 1951, Poway Road was extended from the old highway to the new highway, allowing Poway residents to by-pass the grade as well.

If you find any articles related to the Poway Grade Tunnel, please let us know.           


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Re: The Poway Grade Tunnel
« Reply #1 on: January 15, 2011, 01:20:06 PM »
Well, evidently it was decided to make a new, less winding grade, and to utilize Carroll Canyon instead of San Clemente Canyon.