How do judges assess the value of property rights in the deep underground? Tunneling operations for railway projects require public authorities to acquire property rights on underground volumes corrresponding to the future tunnels. Compensation payable to the private owners is determined by valuation methods used by compulsory purchase judges. Yet, underground property rights defeat normal market valuation and involve a shift towards expert-based valuation.
Two empirical cases, Line 14 in Paris and Crossrail in London, reveal how expertise is used to enable public appropriation in the deep underground. Valuation expertise confer objectivity to prices which cannot be stabilised through reference to market value. However, this research demonstrates that valuation expertise is a fragile epistemic device in compulsory purchase. In Line 14 case, reliance on technical expertise brings uncertainty to the value of
subsoil interests – differing importantly depending on valuation methodology. In Crossrail case, reliance on valuation expertise does not achieve objectivity and disinterestedness. Legal structures enabled a single individual, responsible of land acquisition for railways promoters, to determine the value of any subsoil interest in the United Kingdom. Such tensions on valuation challenge the function of expertise as an alternative mode of veridiction used in judicial
proceedings.