STOPWAY useage
 

What can the STOPWAY be used for.
It clearly is a part of the ASDA so i can use it for the last bits of a reject.

By definition STOPWAY starts where TORA ends but can it be used for the TORA of the opposite runway (Can stopway be used for "initiating the take off run").

Is there a regulation to or against it??

What is declared as stopway may well be unavailable for TORA due to 2nd segment gradient limitations for a close in obstacle. Hence it may well be used for TORA for the opposite direction. Many airports are like this.

Stopway is always available as clearway up to the clearway limit. Stopway is by definition able to be used to stop in the event of RTO.

Other than perhaps specific situations, the general answer is no, one cannot use a stopway to initiate a takeoff from the opposite runway. A stopway doesn't become a "displaced threshold" for the opposite runway.

Generally:

1) A stopway by definition isn't part of the runway (it's an area "beyond the takeoff runway")
2) A stopway might not be constructed to the full strength of the runway
3) There may be other restrictions (e.g. blast areas) preventing use of the stopway as a takeoff surface
4) Taxiways don't serve / extend into stopways

I may be misunderstanding the above, but from my interpretation... no a stopway isn't always available as clearway. In particular, a clearway must be at least 500 ft wide, while a stopway may just be the same width of the runway.

(Clearway - Stopway) could be positive, zero, or negative.

From 14 CFR Part 1

Stopway means an area beyond the takeoff runway, no less wide than the runway and centered upon the extended centerline of the runway, able to support the airplane during an aborted takeoff, without causing structural damage to the airplane, and designated by the airport authorities for use in decelerating the airplane during an aborted takeoff.

Stopway and TORA are defined for EACH runway direction.

Therefore no clear answer to your question can be given due to this physical limitation.
In some cases it is, in other cases it is not, is the only correct answer as it depends on each airport runway end.

If TORA is restricted by obstacles after take-off but there is same runway pavement beyond end of TORA then this can be used as stopway provided Runway End Safety Area (RESA) is provided. If this stopway pavement is same characteristics as the normal runway pavement then it could be used in the opposite direction as part of the beginning of TORA.