United Airlines flies from Houston to Shreveport 4 times a day. Alternatively, Greyhound USA operates a bus from Houston to Shreveport twice daily. Tickets cost $30 - $75 and the journey takes 5 h 46 min.
From Travis St @ Franklin St line 102 bus to Houston airport, fly to Shreveport airport, then taxi to Shreveport. 3 h 4 min $517. From Houston, TX bus to Shreveport, LA. 5 h 46 min $38. From Houston drive to Shreveport. 5 h 5 min $28.