Bike pathBangladesh
1. Bike path
A bike path is a part of a road or a separate route intended primarily or exclusively for people riding bicycles. It may be physically separated from motor traffic, marked on the road surface or identified by traffic signs.
Bike paths may be one-way, two-way or shared with other road users. The permitted users, direction of travel, priority rules and obligation to use the path depend on local traffic signs and regulations.
Does Bangladesh have an official cycle-only route sign?
Yes. The national Road Sign Manual includes Route for Cycles Only, a blue circular sign containing a white pedal-cycle symbol. It identifies a route, track or lane reserved for cyclists; the concept is not limited to a physically separated path.
Mandatory path for cyclists.
English • Traffic sign A40 • Bicycles only. The indicated path or lane is reserved for bicycles. Cyclists must use it.
বাংলা • A40 • শুধু সাইকেলের পথ. চিহ্নিত পথ বা লেন সাইকেলের জন্য সংরক্ষিত। সাইকেল চালকদের এটি ব্যবহার করতে হবে।
Sources
🔗 Commons.wikimedia.org
🔗 Rhd.gov.bd • BRTA • Traffic Signs Manual • A40 • PDF 54
SVG source: Bangladesh Road Transport Authority • Public domain • Original revision 2020-02-16. Wikimedia original unmodified.
Must cyclists use a Bangladeshi route marked by the cycle-only sign?
Yes. The official manual states that cyclists must use the route, track or lane indicated by that sign. This answer concerns the signed reserved facility; it should not be extended to every surface that informally resembles a cycle path.
May motor traffic treat a Bangladeshi cycle-only route as an extra lane?
No. The cycle-only sign reserves the indicated route for pedal cycles. It is a regulatory reservation, rather than merely a suggestion that cyclists may be present. Follow the actual signs instead of assuming that cars or motorcycles share the facility.

Traffic rules
Bangladesh