Solar charging may help in consistently sunny locales. Steam is not as silly as it may seem. Many of us retain an archaic image of steam engines as heavy, bulky, crude, slow, noisy devices that belch black smoke and explode unpredictably. Like an electric motor, a steam engine can be designed to need no clutch or transmission. Probably the worst practical problems of steam engines arise from their working fluid.
Water freezes at common environmental temperatures and corrodes metal engine parts.
Hybrid systems may give the best practical answer. Balloonacy I don't much like airbags. Also, an airbag's inflating charge generates toxic fumes. Probably, an airbag would destroy my glasses and lacerate my face with their fragments. However, seat belts work fine without airbags.