For years there have been concerns about safety along the ICW corridor. Two specific problems became evident in 2006-2007. First, drivers coming up Merrimount were facing significant delays at Island Crest Way. Second, the intersection was experiencing a high rate of serious accidents.
This combination of problems led the city to study the intersection, consider options and eventually install a temporary reconfiguration. The change was made in October 2007.
Here's a chart showing accidents by severity and location along the corridor before the change:

As you can see, before the 2007 reconfiguration, Merrimount stands out as the most serious trouble spot, with a high number of accidents and a high number of injuries and possible injuries. However, it's evident that other intersections along the corridor are accident prone. SE 47th St. and SE 42nd St. are second and third in accidents after Merrimount.
The City's traffic engineering consultant collected traffic volume and speed data from several surrounding points before and after the reconfiguration.
They reported the following key findings to the city:
After further review of options, in June 2008, City Council voted to implement a three lane conversion of Island Crest Way from the 4100 block to SE 53rd St.
Over the summer, concern was expressed by some citizens who felt the Council had made a decision that reached beyond the intersection, yet had not conducted a public process with that scope.
In September, 2008, the Council directed City staff to create a 'Citizen Advisory Panel' (CAP) to review the options for Island Crest Way and the Merrimount intersection and make recommendations about possible future steps.
The CAP met from November, 2008 to January, 2009. It recommended two potential options: A shorter three lane configuration (from Merrimount to 46th St) and a longer three lane configuration (from Merrimount to 53rd St.)
However, soon after the CAP made it's recommendations, a handful of members who had dissented from the majority opinion began a campaign to promote installation of a traffic signal at Merrimount.
The national economic recession caused a sharp downturn in the City's revenue base and led Council to delay a final decision on Island Crest Way. Consideration of options is currently (as of 9/09) scheduled for December, 2009.
Meanwhile the 'temporary reconfiguration' at Merrimount remains in place. Accident data for the corridor from the time of the reconfiguration to the end of 2008 is shown below:

During this period, there were no injury or possible injury accidents at Merrimount...a dramatic improvement. In addition, the number of accidents at Merrimount no longer stands out relative to other intersections along the corridor--with six accidents at Merrimount and six at 47th (which equates to just over five accidents per year). 42nd again comes in third with three accidents during the period (about 2.5 accidents/year).