The Missouri Department of Transportation and the Missouri University of Science and Technology (Rolla) conducted at study of the Single Point Urban Interchange and found several considerations for bicyclists and pedestrians. You can read the entire study here (PDF).

Design of Single Point Urban Interchanges
Missouri Department of Transportation
Missouri University of Science and Technology (formerly University of Missouri, Rolla)
September 2004

Bicycles
The presence of bicycles can affect the decision to choose a SPI.  Due to their slower speeds, bicycles may adversely affect the capacity and operation of motor vehicles at SPI intersections, thereby negating the benefits of choosing a SPI over another interchange alternative.  The required green and all-red clearance intervals necessary for a bicycle to clear most SPI intersections are substantially longer than what is needed for a motor vehicle.  The required extended signal timing increases delay for motorists.  Accommodation of bicyclists through the SPI intersection is an important consideration.  Section 2–800, “Pedestrians and Bicycles” discusses how to accommodate bicyclists through SPI intersections.  (Page 3)

Pedestrians
Because signals at SPI intersections are timed to move motorists efficiently through the intersection, pedestrians normally can only cross a portion of the intersection in a single cycle.  It may take a pedestrian as many as four cycles to cross the separate ramps connections along the local street as opposed to typically two to four crossings at conventional tight diamonds and partial cloverleaf interchanges.  Pedestrians shall be prohibited from crossing the local street within the interchange. (Page 3)

Normally bicycles are allowed to use the traffic lanes or shoulders and can legally turn left at an intersection. In order to accommodate a left turning bicycle in an SPI, longer signal timing is required.  This longer signal timing makes the intersection operate inefficiently.  At three-phase SPI intersections, bicyclists will normally not be turning left onto the freeways but will be proceeding as through traffic along the local cross streets.  (Page 4)

If an SPI is proposed without a separate bicycle facility, it shall be a Compact SPI.  Where a separate bicycle facility is provided in conjunction with an SPI, the following intersection size criteria applies… (Page 9)

To accommodate bicyclists through SPI intersections, all SPI alternatives shall be Compact SPI except as discussed in the following.  If an SPI alternative other than a Compact SPI is chosen, a separate bicycle facility shall be constructed in conjunction with the SPI.  The separate bicycle facility would typically be a bicycle overcrossing or undercrossing and should  be located in the immediate vicinity of the SPI to minimize out of direction travel by bicyclists. (Page 11)

Bicycle push buttons to extend the next through-move green phase for bicyclists have been installed in California (Page 12)