(Portland, OR)  --  Transportation officials say excessive speed was to blame for Portland's deadliest traffic year on record.  The Portland Bureau of Transportation presented a report to City Council yesterday showing excessive speed was a factor in a majority of crashes last year.  The report says 40 of the 69 traffic deaths reported last year were at least partially caused by excessive speed.  The report also found that people experiencing homelessness are disproportionately affected by traffic violence.