The Trump Administration requested $75.1 billion for the Department of Transportation (DOT) for FY2018, 2.6% ($2 billion) less than DOT received in FY2017. The Administration proposed significant cuts in funding for competitive grant programs, zeroing out the TIGER infrastructure investment grant program and the Essential Air Service (EAS) program, and reducing spending on public transportation capital grants and Amtrak's long-distance trains by half or more. Around 75% of DOT's funding is mandatory budgetary authority drawn from trust funds; the Administration's request would have drawn a slightly larger portion (78%) from mandatory budget authority, reducing the amount of discretionary budget authority in DOT's budget from $19.3 billion in 2017 to $16.4 billion for FY2018. On July 21, 2017, the House Committee on Appropriations reported H.R. 3353 . The committee recommended $77.5 billion for DOT, a 0.5% ($430 million) increase over the comparable FY2017 amount and 3% ($2.4 billion) above the Administration request. On July 27, 2017, the Senate Committee on Appropriations reported S. 1655 . It recommended a total of $78.6 billion in new budget authority for DOT for FY2018 ($78.5 billion after scorekeeping adjustments), 2% ($1.6 billion) above the comparable FY2017 amount and 4.7% ($3.5 billion) over the Administration request. Conflicts over funding levels and spending limits for federal agencies delayed action on final FY2018 appropriations until March 2018. Until that time, a series of continuing resolutions provided temporary funding for federal agencies. Finally, after passing legislation raising the spending limits for federal agencies for FY2018, Congress passed an omnibus spending bill, P.L. 115-141 , which included increased spending for most agencies. Title I of Division L, the DOT Appropriations Act, provided $86.2 billion, 11.8% ($9.1 billion) more than in FY2017. DOT's funding arrangements are unusual compared to those of most other federal agencies, in that most of its funding is mandatory budget authority coming from trust funds, and most of its expenditures take the form of grants to states and local government authorities. Discretionary appropriations constitute most, if not all, of the annual funding for most federal agencies. But roughly three-fourths of DOT's funding has come from mandatory budget authority derived from trust funds. A significant increase in discretionary funding for DOT in its FY2018 appropriation changed that proportion slightly, increasing the share of discretionary funding to almost a third of DOT's budget. Table 1 shows the shift in the breakdown between the discretionary and mandatory funding in DOT's budget from FY2017 to FY2018. Two large trust funds, the Highway Trust Fund and the Airport and Airway Trust Fund, have typically provided around 90% of DOT's annual funding in recent years (92% in FY2017), but in FY2018 a significant increase in discretionary budget authority resulted in the proportion drawn from trust funds dropping to 83%, despite the actual amount increasing by $1 billion; see Table 2 . The scale of the funding coming from these trust funds is not entirely obvious in DOT budget tables, because most of the funding from the Airport and Airway Trust Fund is categorized as discretionary budget authority and so is combined with the discretionary budget authority provided from the general fund. Approximately 80% of DOT's funding is distributed to states, local authorities, and Amtrak in the form of grants (see Table 3 ). Of DOT's largest sub-agencies, only the Federal Aviation Administration, which is responsible for the operation of the air traffic control system and employs roughly 83% of DOT's 56,252 employees, many as air traffic controllers, has a budget whose primary expenditure is not grants. Since most DOT funding comes from trust funds whose revenues typically come from taxes, the periodic reauthorizations of the taxes supporting these trust funds, and the apportionment of the budget authority from those trust funds to DOT programs, are a significant aspect of DOT funding. The highway, transit, and rail programs are currently authorized through FY2020, but the authorization for the federal aviation programs was scheduled to expire at the end of FY2017; it was extended to the end of FY2018. Reauthorization of this program may affect both its structure and funding level. In current (nominal) dollars, DOT's nonemergency annual funding has risen from a recent low of $70 billion in FY2012 to $86 billion in FY2018. However, adjusting for inflation tells a different story. DOT's inflation-adjusted funding peaked in FY2010 at $87.5 billion (in constant 2018 dollars) and declined from that point until FY2015, then began rising again in FY2016 (see Figure 1 ). DOT's real funding, adjusted for inflation, was roughly the same in FY2016 and FY2017 as in FY2006; from FY2012-FY2017, DOT's inflation-adjusted funding was lower than during the FY2007-FY2011 period. Table 4 presents a selected account-by-account summary of FY2018 appropriations for DOT, compared to FY2017. Virtually all federal highway funding and most federal transit funding comes from the Highway Trust Fund, whose revenues come largely from the federal motor fuels excise tax ("gas tax"). For several years, annual expenditures from the fund have exceeded revenues; for example, for FY2018, revenues and interest are projected to be approximately $41 billion, while authorized outlays are projected to be approximately $54 billion, and this shortfall is expected to continue. Congress transferred about $143 billion, mostly from the general fund of the Treasury, to the Highway Trust Fund during the period FY2008-FY2016 to keep the trust fund solvent. One reason for the shortfall in the fund is that the federal gas tax has not been raised since 1993. The tax is a fixed amount assessed per gallon of fuel sold, not a percentage of the cost of the fuel sold: Whether a gallon of fuel costs $1 or $4, the highway trust fund receives 18.3 cents for each gallon of gasoline and 24.3 cents for each gallon of diesel. Meanwhile, the value of the gas tax has been diminished by inflation (which has reduced the purchasing power of the revenue raised by the tax) and increasing automobile fuel efficiency (which reduces growth in gasoline sales as vehicles are able to travel farther on a gallon of fuel). The Congressional Budget Office (CBO) has forecast that gasoline consumption will be relatively flat through 2024, as continued increases in the fuel efficiency of the U.S. passenger fleet are projected to offset increases in the number of miles driven. Consequently, CBO expects Highway Trust Fund revenues of $39 billion to $41 billion annually from FY2018 to FY2027, well short of the annual level of projected expenditures from the fund. The Administration did not request any funding for TIGER grants for FY2018. The House committee likewise recommended no funding for FY2018, while the Senate committee recommended $550 million. The Senate bill also recommended that the portion of funding allocated to projects in rural areas be increased from 20% to 30%; the same change was included in the Senate-passed DOT appropriations bills in FY2016 and FY2017, but was not enacted. The enacted bill provided $1.5 billion for the program, increased the portion for projects in rural areas to 30%, and made planning an eligible expense. It also directed DOT to award the grants within 270 days of enactment. The Transportation Investments Generating Economic Recovery (TIGER) grant program originated in the American Recovery and Reinvestment Act ( P.L. 111-5 ), where it was called "national infrastructure investment" (as it has been in subsequent appropriations acts). It is a discretionary grant program intended to address two criticisms of the current structure of federal transportation funding: that virtually all of the funding is distributed to state and local governments, which select projects based on their individual priorities, making it difficult to fund projects that have national or regional impacts but whose costs fall largely on one or two states; and that most federal transportation funding is divided according to mode of transportation, making it difficult for projects in different modes to compete for funds on the basis of comparative benefit. The TIGER program provides grants to projects of national, regional, or metropolitan area significance in various modes on a competitive basis, with recipients selected by DOT. Although the program is, by description, intended to fund projects of national, regional, and metropolitan area significance, in practice its funding has gone more toward projects of regional and metropolitan area significance. In large part this is a function of congressional intent, as Congress has directed that the funds be distributed equitably across geographic areas, between rural and urban areas, and among transportation modes, and has set relatively low minimum grant thresholds ($5 million for urban projects, $1 million for rural projects). Congress has continued to support the TIGER program through annual DOT appropriations. It is heavily oversubscribed; for example, DOT announced that it received applications totaling $9.3 billion for the $500 million available for FY2016 grants. The U.S. Government Accountability Office (GAO) has reported that, while DOT has selection criteria for the TIGER grant program, it has sometimes awarded grants to lower-ranked projects while bypassing higher-ranked projects without explaining why it did so, raising questions about the integrity of the selection process. DOT has responded that while its project rankings are based on transportation-related criteria, such as safety and economic impact, it must sometimes select lower-ranking projects over higher-ranking ones to comply with other selection criteria established by Congress, such as geographic balance and a balance between rural and urban awards. Some critics argue that TIGER grants go disproportionately to urban areas, but for several years Congress directed that at least 20% of TIGER funding should go to projects in rural areas, which roughly equals the proportion of the U.S. population that lives in rural areas (19%, according to the 2010 Census ). In recent years, the Senate had pushed to increase that proportion to 30%, and for FY2018 grants the portion for rural areas was increased to 30%. As Table 5 illustrates, the TIGER grant appropriation process has followed a pattern for several years, with the Obama Administration requesting as much as or more than Congress had previously provided; the House zeroing out the program or proposing a large cut; the Senate proposing an amount similar to the previous appropriation; and Congress agreeing on a final enacted amount similar to the previously enacted amount. The FY2018 appropriations process changed the pattern slightly, in that the Trump Administration requested no funding for TIGER grants. The FY2018 enacted legislation included significant increases in funding for infrastructure for aviation, highways, passenger rail, and transit, in some cases beyond the authorized levels, in other cases provided in newly created accounts. The Essential Air Service program is funded through a combination of mandatory and discretionary budget authority. In addition to the annual discretionary appropriation, there is a mandatory annual authorization, estimated at $119 million for FY2018, financed by overflight fees collected from commercial airlines by FAA. These overflight fees apply to international flights that fly through U.S. airspace, but do not land in or take off from the United States. The fees are to be reasonably related to the costs of providing air traffic services to such flights. As Table 7 shows, the Trump Administration requested no discretionary funding for the EAS program in FY2018, proposing to use only the available mandatory funding for the program; it estimated that $119 million in mandatory funding would be available in FY2018. That would result in a reduction of 56% ($153 million) from the total FY2017 appropriation. The House committee bill recommended a $150 million discretionary appropriation, as was provided in FY2017; combined with the estimated mandatory funding, that would represent a 2.3% ($6 million) increase over FY2017. The Senate committee bill recommended a $155 million discretionary appropriation; combined with the estimated mandatory funding, that would result in a 4.2% ($11 million) increase. The enacted bill provided $155 million in discretionary funding, identical to the Senate bill; combined with an increase in the mandatory funding, EAS received a total of $286 million, a $22 million (8.7%) increase over FY2017. The EAS program seeks to preserve commercial air service to small communities by subsidizing service that would otherwise be unprofitable. The cost of the program in real terms has doubled since FY2008, in part because route reductions by airlines resulted in new communities being added to the program (see Table 8 ). Congress made changes to the program in 2012, including allowing no new entrants, capping the per-passenger subsidy for a community at $1,000, limiting communities that are less than 210 miles from a hub airport to a maximum average subsidy per passenger of $200, and allowing smaller planes to be used for communities with few daily passengers. Supporters of the EAS program contend that preserving airline service to small communities was a commitment Congress made when it deregulated airline service in 1978, anticipating that airlines would reduce or eliminate service to many communities that were too small to make such service economically viable. Supporters also contend that subsidizing air service to smaller communities promotes economic development in rural areas. Critics of the program note that the subsidy cost per passenger is relatively high, that many of the airports in the program have very few passengers, and that some of the airports receiving EAS subsidies are little more than an hour's drive from major airports. In 2008, Congress directed railroads to install positive train control (PTC) on certain segments of the national rail network by the end of 2015. PTC is a communications and signaling system that is capable of preventing incidents caused by train operator or dispatcher error. Freight railroads have reportedly spent billions of dollars thus far to meet this requirement, but most of the track required to have PTC installed was not in compliance at the end of 2015; in October 2015 Congress extended the deadline to the end of 2018—with an option for individual railroads to extend to 2020 with Federal Railroad Administration (FRA) approval. Congress provided $50 million in FY2010 and again in FY2016 for grants to railroads to help cover the expenses of installing PTC, and $199 million in FY2017 to help commuter railroads implement PTC. The Trump Administration's FY2018 budget request did not include any funding for the cost of PTC implementation, nor did the House or Senate Appropriations Committees recommend any funding for this purpose. The enacted FY2018 bill provided $250 million for PTC implementation under the Consolidated Rail Infrastructure and Safety Improvements grant program, and made up to $50 million of Amtrak's National Network grant available for PTC projects on state-supported routes where PTC is not required by law. The RRIF loan program provides direct loans and loan guarantees to state and local governments, government-sponsored entities, and railroads for rehabilitation or development of rail facilities and equipment. The program's resources are relatively lightly used; it is authorized to make up to $35 billion in loans, but has less than $5 billion outstanding, and has made only four loans since 2012. One of the factors that has been cited as reducing the attractiveness of the program is the requirement that loan recipients pay a credit risk premium to offset the risk of their defaulting on their loan. For the first time, the FY2018 appropriation act provided funding ($25 million) to subsidize the cost of the credit risk premium. Another point of contention with the RRIF program has been DOT's failure to repay the credit risk premium to borrowers who have paid off their loans. The program's statute calls for a borrower's credit risk premium to be repaid when all the loans in that cohort of loans have been paid off, but DOT has never defined what a cohort of loans is. Congress has directed DOT to define a cohort as all loans executed in a particular year; it reiterated that directive in the FY2018 appropriations act, and told DOT to repay the credit risk premiums when all loans in a cohort have been repaid. The Passenger Rail Reform and Investment Act of 2015 (Title XI of P.L. 114-94 ) reauthorized Amtrak while changing the structure of its federal grants: instead of getting separate grants for operating and capital expenses, it now receives separate grants for the Northeast Corridor and the rest of its national network. This act also authorized three new programs to make grants to states, public agencies, and rail carriers for intercity passenger rail development: Consolidated Rail Infrastructure and Safety Improvement Grants Federal-State Partnership for State of Good Repair Grants Restoration and Enhancement Grants The Administration's FY2018 budget requested a total of $811 million for intercity passenger rail funding: $760 million for grants to Amtrak and $51 million for two of the new grant programs. The House Appropriations Committee recommended $1.4 billion for Amtrak and a total of $525 million for two of the new grant programs. The Senate committee recommended $1.6 billion for Amtrak and a total of $124 million for the three new grant programs (see Table 9 ). It specified that $41 million of the $124 million recommended for the grant programs could be used to initiate or restore intercity passenger rail services, and advised Amtrak and other stakeholders to seek that funding for restoration of Amtrak's Gulf Coast service, which was interrupted in 2007 and never fully restored. It also noted that funding under the Federal-State Partnership for State of Good Repair program could be used for Amtrak's Hudson Tunnel replacement project (without naming that project). The final FY2018 act provided $1.9 billion for Amtrak, an increase of 30% ($447 million) over FY2017, and a total of $863 million for the new grant programs. The $98 million provided for the three new intercity passenger rail grants in FY2017 was the first funding provided for intercity passenger rail (other than annual grants to Amtrak and the occasional grants for PTC implementation) since the 111 th Congress (2009-2010), which provided $10.5 billion for DOT's high-speed and intercity passenger rail grant program. From FY2011 to FY2016, Congress provided no funding for intercity passenger rail development, and in FY2011 it rescinded $400 million that had been appropriated for that purpose but not yet obligated. The majority of the Federal Transit Administration's (FTA's) roughly $12 billion in funding is funneled to state and local transit agencies through several programs that distribute the funding by formula. Of the few transit grant programs that are discretionary (i.e., awarding funding to applicants selectively, usually on a competitive basis), the largest is the Capital Investment Grants program (often referred to as the New Starts program, as that is the largest and best known of its component grant programs). It funds new fixed-guideway transit lines and extensions to existing lines. The program has three components: New Starts funds capital projects with total costs over $300 million that are seeking more than $100 million in federal funding; Small Starts funds capital projects with total costs under $300 million that are seeking less than $100 million in federal funding; and Core Capacity grants are for projects that will increase the capacity of existing systems. There is also an Expedited Project Delivery Pilot, intended to provide funding for eight projects eligible for any of the three programs that require no more than a 25% federal share and are supported, in part, by a public-private partnership. Grant funds for large projects are typically disbursed over a period of years. Much of the funding for this program each year is committed to projects already under construction with multiyear grant agreements signed in previous years. For FY2018, the Trump Administration requested $1.2 billion for Capital Investment Grants, 50% ($1.323 billion) less than the $2.4 billion provided in FY2017. The Administration stated an intention to approve no new projects, only to provide funding to projects that had previously been approved for funding. The Administration request noted that there were "66 projects in the program seeking funding, more than at any time in the program's 30-year history—a clear indication of the intense demand from communities around the United States for new and expanded transit services." The House Committee on Appropriations recommended $1.8 billion, which is 42% ($521 million) more than requested but 27% ($660 million) below the FY2017 level. The House committee did not recommend funding for any new projects during FY2018, save for funding that appears to be provided for Amtrak's Hudson Tunnel project. The Senate Committee on Appropriations recommended $2.1 billion, 73% ($901 million) more than requested but 12% ($280 million) below the FY2017 level. The final FY2018 act provided $2.6 billion, 9.6% ($232 million) more than the FY2017 level, and over twice the amount requested by the Administration. The division of funding among the components of the Capital Investment Grants program is shown in Table 10 . Perhaps due to concerns about whether the Administration would make use of the grant funding provided in excess of the requested amount, both the House and Senate committee bills included language directing DOT to carry out the Capital Investment Program as described in statute; the enacted bill included that language, and added a directive to DOT to obligate $2.253 billion by December 31, 2019 (the amounts appropriated for Capital Investment Grants are available for obligation for four years). A New Starts grant, by statute, can be up to 80% of the net capital project cost. Since FY2002, DOT appropriations acts have included a provision directing FTA not to sign any full funding grant agreements for New Starts projects that would provide a federal share of more than 60%. The House-reported bill included a provision prohibiting grant agreements with a federal share greater than 50%. That provision was not included in the Senate-reported bill. The enacted bill followed the House lead in reducing the federal share, with a provision prohibiting New Starts grant agreements with a federal share greater than 51%. Critics of lowering the federal share provided for New Starts projects note that the federal share for highway projects is typically 80%, and in some cases is higher. They contend that the higher federal share makes highway projects relatively more attractive than public transportation projects for communities considering how to address transportation problems. Advocates of this provision note that the demand for New Starts funding greatly exceeds the amount available, so requiring a higher local match allows FTA to support more projects with the available funding. They also assert that requiring a higher local match likely encourages communities to estimate the costs and benefits of proposed transit projects more carefully, reducing the risk of subsequent cost overruns and of project ridership falling short of expectations. Among the challenges to funding transportation infrastructure is that most federal transportation funding is distributed by mode, and most of the funding is distributed to states by formula. There are grant programs reserved for highways, for public transportation, for rail, and for airport development, but sponsors of projects involving multiple modes may have difficulty amassing significant amounts of federal funding. And while Congress provides some $55 billion annually for surface transportation programs, the vast majority of that funding is automatically divided among the states, making it difficult for a state to accumulate the funding needed for a major project in addition to meeting its other needs. One project that is highlighting this situation is Amtrak's Gateway Program, and specifically the Hudson Tunnel replacement project. Amtrak's Gateway Program is a set of projects intended to increase capacity and reliability of rail service between northern New Jersey and Manhattan, the most heavily used section of intercity and commuter rail track in the nation. The program would replace bridges, expand track capacity from two to four parallel tracks, and, most critically, add a new rail tunnel under the Hudson River. The existing tunnel, the only link connecting the Northeast Corridor from New Jersey to New York, is over a century old, was flooded with seawater during Hurricane Sandy, and is deteriorating. The estimated cost of the Gateway Program is at least $24 billion, and likely will increase as project planning advances; the estimated cost of just the new Hudson Tunnel is $11.1 billion. Since the new tunnel would carry both intercity and commuter rail traffic, it is eligible for DOT funding from both the intercity rail program and the public transportation Capital Investment Grants program. But other than the annual grants to keep Amtrak going, relatively little funding has been available in recent for intercity rail projects: the largest rail grant program in FY2017 was funded at $68 million. The Capital Investment Grants program has significantly more funding to award—$2.4 billion in FY2017—but competition for that funding is intense, and the largest grant awarded to a project in the past 10 years was $2.6 billion. In 2016, under the Obama Administration, media reports indicated an agreement had been reached between DOT, Amtrak, and the states of New Jersey and New York to share the costs of building the new Hudson Tunnel, with one-third to be covered each by DOT/Amtrak, New Jersey/New Jersey Transit, and New York State. The Trump Administration's position on sharing the cost of the new tunnel is unknown. In any case, it would be up to Congress to provide the money. The House Appropriations Committee did not mention the Gateway Program or Hudson Tunnel project in its FY2018 THUD committee report, nor did it provide a significant amount of additional funding to any grant program. The committee recommended zeroing out the TIGER Grant Program, which could be one source of money for the Hudson Tunnel project, and cutting funding to the Capital Investment Grants program, another potential source, by $660 million from its FY2017 level. But the committee report noted that its Capital Investment Grants program funding recommendation included $400 million for new projects that meet the criteria of 49 U.S.C. §5309(q): "joint public transportation and intercity passenger rail projects." The Senate Appropriations Committee did not recommend any specific funding for the Hudson Tunnel replacement. It noted that FRA's Federal-State State of Good Repair grant program could be a source of funding for projects similar to those in the Gateway Program, and encouraged Amtrak to use the $358 million recommended for its Northeast Corridor account to continue its Gateway Project. The enacted bill did not mention the Gateway Program or Hudson Tunnel project. But it provided Amtrak almost $300 million more than Amtrak requested for its Northeast Corridor, and increased funding for FRA's State of Good Repair program from $25 million in FY2017 to $250 million for FY2018, as well as increased funding for the TIGER grant prog ram and FTA's Capital Investment Grants program. The Passenger Rail Investment and Improvement Act of 2008 authorized $1.5 billion over 10 years in grants to the Washington Metropolitan Area Transit Authority (WMATA) for preventive maintenance and capital grants, to be matched by funding from the District of Columbia and the states of Maryland and Virginia. Under this agreement, Congress has provided $150 million to WMATA in each of the past nine years. WMATA faces a number of difficulties. It is dealing with a backlog of maintenance needs due to inadequate maintenance investment over many years, and it has experienced several fatal incidents, most recently in January 2015. A number of other incidents have raised questions about the safety culture of the agency. An investigation that found numerous instances of mismanagement of federal funding led FTA to restrict WMATA's use of federal funds. An FTA audit of WMATA's safety practices in 2015 produced many recommendations for change, and in October 2015 FTA assumed oversight of WMATA's safety compliance practices from the Tri-State Oversight Committee, the agency created by the governments of the District of Columbia, Maryland, and Virginia to oversee WMATA safety performance. FTA continues to exercise safety oversight of WMATA, conducting inspections, leading accident investigations, and directing that federal funds received by WMATA are used to improve safety. In February 2017, FTA notified leaders of the three jurisdictions that it would withhold 5% of their FY2017 transit Urbanized Area formula funds until they meet the requirements to create a new State Safety Oversight Program to replace the Tri-State Oversight Committee. The jurisdictions passed legislation establishing a new safety oversight agency soon after, but the agency must be in operation before FTA will release the funding. The National Transportation Safety Board has recommended that oversight of WMATA's rail operations be assigned to FRA, which has a long history of safety enforcement, rather than FTA, which is primarily a grant management agency. However, Congress would have to act to give FRA authority to oversee WMATA, while FTA already has such authority. For FY2018, the final year of the grant authorization, both the House and Senate Appropriations Committees recommended the full $150 million annual grant for WMATA. The Senate committee report expresses frustration at the slow progress WMATA has made in providing wireless service throughout its system, which Congress mandated in 2008. The Senate committee report also notes that the FY2018 grant is the final installment of the $1.5 billion funding commitment Congress made in 2008, but that WMATA's budget assumes that the annual funding will continue to be provided. The enacted bill provided the $150 million, and made grants to WMATA contingent on improvements to its safety management system.

Summary: Congress appropriated $86.2 billion for the Department of Transportation (DOT) for FY2018. This represented a $9.1 billion (11.8%) increase over the amount provided in FY2017. The principal reason for the higher spending level was increases in funding from the general fund for highways, public transportation capital investments, and passenger rail projects. The appropriation was included in an omnibus spending bill, P.L. 115-141, Title I of Division L, the DOT Appropriations Act. The DOT appropriations bill funds federal programs covering aviation, highways and highway safety, public transit, intercity rail, maritime safety, pipelines, and related activities. Federal highway, transit, and rail programs were reauthorized in fall 2015, and their future funding authorizations were somewhat increased. The Trump Administration proposed a $75 billion budget for DOT for FY2018, including $16.4 billion in discretionary funding and $58.7 billion in mandatory funding. That was approximately $2 billion less than was provided for FY2017. The budget request reflected the Administration's call for significant cuts in funding for transit and rail programs. The annual appropriations for DOT are combined with those for the Department of Housing and Urban Development (HUD) in the Transportation, Housing and Urban Development, and Related Agencies (THUD) appropriations bill. The House Appropriations Committee reported H.R. 3353, the THUD FY2018 appropriations bill, in which Division A provided FY2018 appropriations for DOT. The committee recommended $77.5 billion in new budget authority for DOT, 0.5% ($400 million) more than ultimately approved for FY2017 and roughly 3% ($2.4 billion) more than the Administration requested. The Senate Appropriations Committee reported out an FY2018 THUD bill, S. 1655, which was not taken up by the full Senate. The Senate committee recommended $78.6 billion in new budget authority, 2% ($1.6 billion) more than the comparable FY2017 amount and 4.7% ($3.5 billion) more than the Administration requested. Conflicts over funding levels and limits delayed action on final FY2018 appropriations until March 2018. Until that time, a series of continuing resolutions provided temporary funding for federal agencies. There is general agreement that more funding is needed for transportation infrastructure, and the Trump Administration has proposed an increase in spending on infrastructure, but Congress has not been able to agree on a source that could provide the additional funding. The federal excise tax on motor fuel, which is the primary funding source for federal highway and transit programs, has not been increased in over 20 years, and does not raise enough revenue to support even the current level of spending. To address this shortfall, Congress has transferred money from the general fund to the Highway Trust Fund on several occasions since 2008 to provide sufficient funding for the programs. Revenue estimates by the Congressional Budget Office (CBO) suggest that general fund transfers will continue to be required in future years to support the currently authorized level of highway and public transportation spending.