within countries if households live in urban or rural areas and based on their income. Based on the reviews, the paper ends on a standard set of guidelines and sample questions to be integrated into future household surveys, with a particular focus on questions related to climate change and road safety. Including more detailed questions on the type of vehicles owned by households can be used to understand the efficiency and redistributive impacts of restrictions on vehicle type or fuel taxes motivated by climate-change concerns. Including questions related to traffic accidents can be used to better quantify the gains from improving road safety.

A few papers have used household surveys to understand transport choices and expenditures. Gandelman et al. (2019) look at transportation affordability in Latin America and the Caribbean (LAC), with a focus on urban public transportation. They provide analysis of transportation expenditures across income groups and build a transportation affordability indicator to rank cities in accordance with their performance. In a companion paper, Gandelman and co-authors (2018) provide detailed transport expenditure patterns for Latin American countries and calculate income elasticities per mode of transportation. This study extends the work to countries outside Latin America. Finally, related work on transport affordability by Estache et al. (2018) was conducted for a sample of 90 countries for developing and emerging economies and for 26 European countries, as a proxy for developed countries practice. In a recent study, Mitra et al. (2021) investigated the nationally representative surveys and censuses in Low and MiddleIncome Countries (LMICs) for tracking the incidence of deaths and injuries from road traffic crashes in LMICs to see if these population-level data sources can be utilized to monitor progress made in SDG 3.6. The authors concluded that relatively small modifications and additions to questions in forthcoming surveys could provide countries with a way to benchmark their existing surveillance systems and result in a substantial increase in data for tracking road traffic injuries globally.

The contributions of the paper are twofold. This paper provides a unique review of transportrelated questions in LSMS surveys and discusses possible improvements to facilitate the harmonization of questions in future rounds and the inclusion of questions useful for climate change and road safety topics. This paper covers many countries and goes beyond affordability issues by collecting questions on accessibility, ownership, and transport behaviors in LSMS and harmonized datasets.

The first part of the paper reviews transport-related questions included in LSMS surveys. The second part reviews transport-related questions in non-LSMS surveys. The third part focuses on two harmonized surveys to show the potentials for more harmonization efforts. The last part concludes by providing a module complementary to the existing LSMS household surveys covering multiple aspects linked to transportation issues.

# **2. Transport-Related Questions in LSMS Surveys**

Multiple sources could be used to collect household-level information to learn about transport. Table 1 lists a variety of instruments for collecting households’ information. For the sake of this 3