A bio-modified bitumen includes bitumen including organic compounds, and a bio-oil including phenolic compounds and derived from wood biomass. An organic compound includes a volatile organic compound. A phenolic compound forms hydrogen bonds, covalent bonds, or both with an organic compound in the bitumen. Suitable phenolic compounds include phenol, 2,6-dimethylphenol, 2,6-dimethoxyphenol, benzene-1,2-diol, 4-methylbenzene-1,2-diol, 2-methoxy-4-methylphenol, 4-ethenyl-2-methoxyphenol, and 2-methoxy-4-(prop-2-en-1-yl)phenol.