Impact News reports on how Houston Metro (Metropolitan Transit Authority of Harris County) is raising toll rates on several HOT lanes to reduce peak congestion on the lanes, but paradoxically also increasing the hours during which HOVs can use the lanes.
Typically HOT lanes have evolved in the US as HOV lanes were often undertutilised, and transport authorities wished to get better use by charging other motorists to use the valuable capacity. Houston has taken quite a different approach, because it appears that its HOV capacity is not underutilised at peak times.
As such, its HOT lanes are HOV only at the peak, the economic assumption being that high-occupancy vehicles are a more valuable use of the road space than anyone willing to pay a toll.
So in response to growing peak congestion, it is increasing the period of exclusive HOV usage and increasing tolls at the either side of that period.
Now the policy position at Houston is that the lanes exist for HOVs first and foremost, which is all very well, except that it isn’t sustainable. Ultimately, if demand continues to grow to use these lanes, like others, then they will be congested, and either more capacity will be needed, or the lanes will have to be priced – for all users.
I’ve never been convinced that HOV lanes are a good response to the demand/capacity problem of highways, if only because they are predicated on vehicles with multiple occupants having a higher value of time than those with one and on incentivising more efficient use of road space, by making car-sharing more attractive. However, one survey from the State of Washington indicates that by far the most prevalent car sharing is that of household members, indicating that in many cases use of such lanes is fortuitous rather than planned. A California PATH Research Report undertaken by the University of California, Berkeley, indicated that HOV lane systems don’t actually add capacity compared to conventional lanes claiming that “A system with one HOV lane and three general purpose lanes carries the same number of persons per hour as a system with four general purpose lanes”. That may counter-intuitive, but it reflects actual behaviour rather than the wishful thinking of some policy makers.
Surely a better approach would be to charge all users. The price per user would be spread across multiple individuals for HOVs, which would give a more equitable indication of the value of the scarce resource (road space) for those using it. It would also provide a revenue stream that may eventually be leveraged to provide more capacity if pricing gets particularly high. Meanwhile, raising the HOV threshold to three or more occupants and then four, may be an interim measure, but leaves the question of excluding a wider group of users from the lanes at the time they most want to use them.
Those motorists unhappy about paying have always got a choice, they can use the untolled lanes that everyone else uses, including freight (which almost never is offered similar opportunities to save time and avoid congestion, even though the costs of delay for trucks can be significantly higher than that for car users).
Houston’s approach appears to be “buying time”, but I think the next obvious step is to start charging for HOV use at peak times. The case for pure HOV lanes is not clear, and the Houston policy will need to be revisited sooner or later. Bear in mind that Houston Metro is a transit authority, which means it is driven by promoting use of public transport in the city. Whether that necessarily fits in best with maximising the efficient use of the existing highway network is not clear.