Dr. Solari was one of the first traffic authorities in Europe.  His traffic engineering contributions  included the first comprehensive traffic survey ever conducted in Europe which was made in     Milan, Italy.  Under the sponsorship of the Italian government he studied traffic conditions in mot countries of Europe and in the United States.  He spent a year each in the Berlin Police Department and Scotland Yard as a guest officer.  He also served as Commander-in-Chief of the Milan Municipal Police Force for many years.  He received six Italian decorations, four of which were for bravery and was made a Commander of the Crown of Italy by the King of Italy.