SR 15A begins at the intersection of US 17/92 as a western continuation of East Taylor Road, which from there runs east to CR 4101. It forms a western truck bypass for the aforementioned routes around DeLand, and begins to curve to the northwest just before the intersection with South Adelle Avenue while West Taylor Road resumes in a realigned road just south of the intersection with SR 15A and South Adelle, which returns to the original trajectory that SR 15A replaced. North of the intersection with West Beresford Avenue it becomes part of South Spring Garden Boulevard. Along the way, the otherwise minor intersection with Camphor Lane leads to the NRHP-listed John B. Stetson House. The sole intersection with a state route along this road, other than those at the termini is Florida State Road 44, and South Spring Garden Boulevard becomes North Spring Garden Boulevard. Additionally, SR 15A becomes not only a truck bypass for US 17 and 92, but for SR 44 north of this point. Along the way, North Spring Garden Boulevard encounters a grade crossing with CSXDeLand Spur, and former industrial areas can be found in the vicinity of the crossing between Wisconsin and Minnesota Avenues, primarily along the east side. North of Plymouth Avenue, the road changes from a four-lane undivided highway to a four-lane divided one. The truck bypasses for US 92 and SR 44 along SR 15A end at the intersection of Volusia County Road 92, across the street from Grantham Way, the latter of which is the entrance to the Glenwood Springsresidential community. VCR 92 connects to motorists and truck drivers the northern end of the US 17/92 overlap. North of that intersection, SR 15A leaves the city limits and runs through semi-rural surroundings in unincorporated segments of Volusia County. The only signalized intersection in this vicinity is with Glenwood Road, an unmarked west to east county road that leaves its community namesake immediately west of the intersection with SR 15A, and has an eastern terminus at the fork in the road with US 17 and SR 11. The last intersection before the route's northern terminus is two streets obstructed by the divider; Tall Oaks Road leading from the southbound lanes and Williamsbridge Road leading from the northbound lanes. After this SR 15A curves to the northeast and terminates at US 17/FL 15, north of DeLand. It continues northeast from its northern end as CR 15A to SR 11.
Major intersections
History
SR 15A used to include CR 15A, which continues the bypass to SR 11. It also used to include SR 472.
Former sections
Several former sections of SR 15A have existed throughout the state within the vicinity of SR 15. These include SR 139 heading northwest out of downtown Jacksonville as a hidden route for U.S. Route 23, SR 551 east of Orlando, and SR 729 in Pahokee. One notable section was from US 17 Roosevelt Boulevard on US 17 AltRoosevelt Expressway until ending on eastbound Interstate 10. With the realignment of US 17 onto the Roosevelt Expressway, that segment became part of SR 15. Other sections of SR 15A have existed:
SR 15A, now CR 15A, connected SR 15/SR 700 at Upthegrove Beach to SR 710. At the same time, SR 15B connected the same two highways near the Okeechobee-Martin County boundary line about to the southeast.
Several short sections of SR 15A spurred from SR 15 in and near Orange Park. Some or all may now be CR 15A.
SR 15A, now CR 15A, connected SR 15 southeast of downtown Callahan to SR 200 southwest of downtown Callahan.
Historic State Road 15C
In addition to the former SR 15B noted above, Okeechobee County also had a State Road 15C. Now CR 15C, it was, and still is, an eastward spur from SR 15 near Fort Drum.